Finding Ancient Rome

Walks in the City

Paula Landart

© Paula Landart, 2014.
First published January 2014. Updated October 2014. SSE1413401155
Sample chapter: The Campus Martius.

Note: Links pointing to other chapters of the book are inactive.

Contents

1. Isola Tiberina

1. It All Started Here

2. Itinerary for the Isola Tiberina

3. Along Via della Lungaretta

4. Broken Bridges

5. The Island of Health

6. Faith, Hope, and Broccoli

7. At the Elephant

8. Sant’Omobono

9. From Pales to Palace, from Sheep-girl to Dea Roma

10. About...

2. The Roman Triumph

1. The God Wore Purple

2. Itinerary for the Roman Triumph

3. Triumph I: Porticus Octaviae to the Forum Holitorium

1. Mustering for a Triumph

2. A Good Place to Camp

3. Memento mori

4. Porticus Octaviae

5. Teatro di Marcello

6. Temples of Apollo Sosianus and Bellona

7. At the Porta Triumphalis

8. At the Portus Tiberinus

4. Triumph II: Through the Forum Boarium to the Circus

1. Of Cows and Heroes

2. Piazza Bocca della VeritÀ

3. The Great Altar of Hercules

4. At the Circus

5. Triumph III: From the Circus to the Arch of Constantine

1. The Long Stretch to the Via Sacra

2. Via dei Trionfi

6. Triumph IV: from the Arch of Constantine to the Mamertine Prison

1. Turning the Meta Sudans

2. Via dei Fori Imperiali

3. The Basilica of Maxentius

4. The Temple of Peace

5. The Temple of Antoninus Pius and Faustina

6. The Forum

7. The Forum of Caesar and the Temple of Venus Genetrix

8. The Severan Arch

9. The Stairs of Mourning

10. Triumph V: From Juno Moneta to Jupiter Capitolinus

11. Up to the Capitol

12. About...

7. Clivus Suburanus

1. An Ancient Commute

2. Itinerary for the Clivus Suburanus

3. A bit of a very old wall

4. Entering the city

5. At the Esquiline Forum

6. Down the Clivus to Mercurius Sobrius

7. The Lacus Orphei

8. War among the Barons

9. To the Porticus Liviae

10. The Argiletum

11. About...

8. Campus Martius

1. Battles, Blood, and Rage

2. The Field of Mars

3. Itinerary for the Campus Martius

4. Marcus Agrippa the Generous and the Clean

5. The Basilica of Neptune

6. The Pantheon Unexplained

7. The Baths of Nero

8. Isis and Serapis in the Campus Martius

9. The Imperial Cult

10. A Divine Mother-in-Law

11. The Clock That Never Struck

12. The Column of Marcus Aurelius

13. About...

9. Buried by the Tiber

1. The Tombs of Two Emperors

2. Itinerary for the Tombs of the Two Emperors

3. The most magnificent tomb in the empire

4. The Mausoleum of Hadrian

5. Bridge of the Emperor, Bridge of the Angels

6. About...

10. Roman Theatres in the Campus Martius

1. After the Last Show

2. Itinerary for Roman Theatres

3. Largo Argentina

4. Via delle Botteghe Oscure

5. A Funny Thing Happened on the Way to the Middle Ages

6. The Best Seat in the House, the Best House in the Seats

7. Lost Melodies

8. The Stadium of Domitian

9. About...

11. The Baths of Diocletian

1. Something To Remember Me By

2. Itinerary for the Baths of Diocletian

3. Pleasure Gardens of the Renaissance

4. A Puzzle Solved

5. From Bath to Bernard

6. A Quiet and Refined Neighbourhood

7. One of the Seven

8. Water from the Rock

9. Santa Maria degli Angeli

10. The Eastern Buildings and the Perimeter Wall

11. About...

12. Valley of the Caffarella

1. The Endless Tears of Egeria

2. Itinerary for the Valley of the Caffarella

3. The way to the Caffarella

4. The perils of the Appian Way

5. Through the Gate

6. The Nymphaeum

7. A Temple, a Tomb, a Church: Sant’Urbano

8. Torre Valca

9. The Springs

10. About...

13. Public Transport

14. Who’s Who

15. Glossaries

1. Latin Glossary

2. Italian Glossary

16. Image Credits

17. Sources

18. General Bibliography

19. Acknowledgements

Campus Martius

Battles, Blood, and Rage

For I shall sing of Battels, Blood and Rage,
Which Princes and their People did engage,
And haughty Souls, that mov’d with mutual Hate,
In fighting Fields pursued and found their Fate
– Virgil, The Aeneid, 19 BC. Book VII, verse 40. Translated by John Dryden (1697).

The empire was forged on the Field of Mars, where Roman soldiers drilled and armies assembled under the auspices of the god of war. Here, outside the pomerium, men could bear weapons, the Senate could meet generals in arms and foreign envoys, foreign gods could be worshipped.

With the advent of the Pax Romana, the Campus Martius was singularly marked by two friends, Agrippa, the great general, and Octavian, the first emperor, who built monuments there to celebrate not war but peace.

By the end of the first century AD, the central Campus Martius was filled to bursting with public buildings, houses, baths, theatres, temples, and monuments.
Five centuries later, when mighty Rome was a thing of the past and the aqueducts were cut or in disrepair, people concentrated in this area close to the Tiber, their only water supply, making their houses, shops, and churches in the magnificent remains. Those ancient walls form the modern fabric of this part of Rome, which then like today, was busy, noisy, crowded, confusing, and fascinating.

Below: The Roman Army on the march. Soldiers and standard-bearers (wearing animal heads, the emblems of their cohort) on the Column of Marcus Aurelius.

The Field of Mars

Before the 1st century AD, this floodplain was a sort of commons belonging to everyone, used for pasture, as drilling grounds, and for assembling armies. Livy tells us that the Senate gave it as plunder to the Roman people after the expulsion of the king Tarquin the Proud (~509 BC), and from that time onward it was sacred to Mars. The only shrine there in those early days was the Altar of Mars, which the Romans said was raised by king Numa Pompilius himself (legendary reign 715–673 BC).
But all that changed once the city started bursting out of its walls around 100 BC, and the Senate ceded bits of land to men like Pompey, who built his theatre there.

Itinerary for the Campus Martius

Below: Route. Approximate length of walk: 1.89 km (1.18 mile)

Itinerary on Google Maps
Public transport to the start of the walk.
Marcus Agrippa the Generous and the Clean

By the time of his death in 12 BC, a large piece of the central Campus Martius was the personal property of Marcus Vipsanius Agrippa. In his will, he left his gardens and baths to the Roman people. Agrippa also made provisions to cover the costs of running the baths, so for a time after his death, Romans could bathe there for free. These were the first public baths in Rome, the first of those bathing establishments that would become a hallmark of Roman civilisation, guarantors of health and cleanliness.

Agrippa’s baths and the Pantheon are far from being completely understood – they are full of puzzles and mysteries which drive archaeologists around in circles. To this day, the early history of the Pantheon and its relation if any to the baths is unclear.

Below: Agrippa’s Baths and the Pantheon, remains mapped onto present-day streets.

Take the Via di Torre Argentina on the northeast corner of Largo Argentina toward the Pantheon, then take your first right onto the Via dell’Arco della Ciambella. This street runs directly through the Baths of Agrippa, and most notably right through what was once a circular room crowned by a dome 25 metres in diameter. Its function is unknown: some speculate that it was a frigidarium, others say it was a hall.

Below: Remains of a circular domed room of Agrippa’s Baths in Via dell’Arco della Ciambella.

About half of the structure survives. Houses have been built up against its walls.

Below: Visible remains of the Baths of Agrippa, mapped onto present-day streets.

Baths usually had a tiled cold-water swimming pool, but Agrippa’s baths had instead a whole lake, the Stagnum Agrippae, “Agrippa’s Lake”, in what was once a low-lying marsh. Beyond the lake to the west was the Nemus Agrippae, “Agrippa’s Wood”, which later became the site for Domitian’s Odeon and Stadium.

At the end of the Via dell’Arco della Ciambella, turn left on the Via dei Cestari and continue straight on through the Piazza della Minerva, so named because the ruins here were vaguely remembered as belonging to some goddess or the other. (She was Isis, who by the 8th century had been long forgotten. In fact a smaller temple of Minerva, Minerva Chalcidica, is indeed nearby, as we shall see later.) Even more confusing, what people thought were the ruins of a temple actually part of the “voting pens”, which we will take a look at now.
When you see the bulk of the Pantheon, turn left onto the Via della Palombella, and pause for a moment at the corner to look at the remains of the porticus of the Saepta Iulia, where Romans once came to cast their ballots.

Below: The broken wall is part of the western portico of the Voting Pens.

According to Cassius Dio, in 25 BC Agrippa, that great naval commander, built a stoa, a covered colonnade, dedicated to Poseidon (Neptune in Latin) to commemorate his victories at sea. This colonnade is now securely identified with these same ruins, part of the western portico of the Saepta. It was called the Porticus Argonautarum because it was painted with scenes from the Voyage of the Argo. And nearby, says Dio, Agrippa built another structure called the Poseidonion, today assumed to be the Basilica of Neptune, although what we see today is certainly not Agrippa’s original, since Dio tells us everything burned in 80 AD.

The Basilica of Neptune

Proceed just a few meters along the Via della Palombella, along what today is the back wall of the Pantheon. On this wall are fragments of a white travertine cornice decorated with marine motifs, on either side of a central arch.
The white cornice and columns were part of the interior of the Basilica of Neptune or Neptunium, or Poseidonion, most of which lies in and under the Via della Palombella and the buildings to the south.
In 1882 and 1928, the original Republican-era streets here were discovered, showing that the entrance to the rotunda was once to the south, about where the central arch is; an arched passageway connected it to the Basilica of Neptune. The underlying foundation is shared with the rotunda behind (which is not the case for the monumental entrance on the north side). This entrance was blocked up at some time, perhaps when Hadrian restored the rotunda.

Below: The frieze and columns on the south side of the Pantheon, part of the “Basilica of Neptune”.

Thus, according to some archaeologists, the early “Basilica of Neptune” could have been part of the baths, perhaps the south-facing laconicum, a hot room. It was covered with a roof consisting of three cross-vaults, bits of which were found during excavations in 1881-1882 (along with the skeleton of a man apparently killed when the vaulted roof finally collapsed). Cassius Dio tells us that the basilica burned in the fire of 80 AD, and Hadrian’s biographers list it among the buildings he restored some 30 years later. By that time, it was possibly used as a meeting-place and housed shops (and thus fulfilled the functions of a basilica).

At the end of the Via della Palombella, turn right onto the Via della Rotonda, and walk ahead to the Piazza della Rotonda and the Pantheon.

The Pantheon Unexplained

Rivers of ink and forests of paper have been devoted to the Pantheon, the strangest of all buildings that have come to us from antiquity. The large, light and stable dome with its oculus does not match up with the porch. The inscription proclaims that Agrippa built it but bricks date it to over a century after his death. Columns are of different heights, stairs buried, halls walled up, two pavements lie below it and two pediments before it. Was the rotunda with its oculus built by Agrippa, then restored by the emperor Hadrian? Or was the whole thing built by Hadrian? Or by Trajan? Could the famous hemispherical interior with its rectangular front be just an accident due to restoring and re-using a damaged building?
The debate is endless, because the Pantheon has not given up its secrets, not least because it has come to us intact thanks to its early conversion to a church, Santa Maria ad Martyres. And not least because of its great age and importance, and because over six million people visit it each year. It cannot be taken apart for study, and even if it could, concrete and brick cannot by themselves tell us its history.
Archaeologists are divided, and each has an opinion. Walking around the Pantheon and looking at all its wonders and oddities is the best way to form your own.

First proceed diagonally across the Piazza della Rotonda, past the fountain, to the corner of the piazza and Via dei Pastini, where there is a little bar (2013). This is just about the only spot from which the rectangular “transitional block” and the double pediment of the Pantheon can be seen.

Below: The higher pediment on the transitional block of the Pantheon, from Via dei Pastini.

What was the reason for the higher pediment? The usual explanation is “they ran out of 50-foot (Roman feet) granite shafts”, and having only 40-foot shafts, had to build the portico much lower. Yet there is no proof for this and not all archaeologists accept that idea.

An interesting thing about the lower pediment was the find made in the 1930s on the travertine pavement in front of the Mausoleum of Augustus. Lines drawn in that pavement show that the stones for the pediment were cut and set up there, flat on the ground, before being transported here and mounted. The ground height of the stonecutter’s incised lines, much higher than the ground level of the tomb, tells us that this work was done when both Agrippa and Augustus were long dead, perhaps as much as a century later: the time of emperor Hadrian.
Equally strange, there is a 2-5 cm gap between the transitional block and the rotunda, which some take as proof the porch was built at a later date.

Finally, the inscription on the pediment:

M – AGRIPPA – L – F – COS – TERTIUM – FECIT

proclaims that Marcus Agrippa, son of Lucius, built this when he was consul for the third time, which would have been 27 BC. Up to 1890, before brickstamps from ~100-130 AD were found in the rotunda, everyone believed that the Pantheon as it stood was the work of Marcus Agrippa, on the basis of this sole inscription. But in the biography of the emperor Hadrian (reign 117-138 AD) written in the 4th century AD, the Historia Augustae, we read:

“At Rome he restored the Pantheon, the Voting-enclosure, the Basilica of Neptune, very many temples, the Forum of Augustus, the Baths of Agrippa, and dedicated all of them in the names of their original builders.”
–Aelius Spartianus, The Life of Hadrian.

Quod non fecerunt barbari...

“What the barbarians did not do, the Barberini did.”
–Anonymous 17th century, posted on Pasquino, one of the Talking Statues of Rome.

Next proceed into the grandiose eight-column portico leading to the entrance, and have a look at its humble ceiling.

Below: The wooden ceiling of the portico.

Here we are looking at bare roof tiles resting on wooden beams, instead of the bronze beams and bronze suspended ceiling that survived until pope Urban VIII Barberini (pontificate 1623-1644) removed them in order to cast 110 cannons for Castel Sant’Angelo.

And below this humble ceiling is the only door in the rotunda, the great double bronze door which was long thought to be a later replacement for the original, mainly because of the frame on either side and the grille above, which caused archaeologists to comment that it was too small for the opening. In fact, when at last the bronze was carefully studied, these were found to be original Roman doors, one of the rare survivals of monumental bronze. They had been cleaned in the course of the centuries, Christian motifs applied, but analysis of the fusion technique left no doubt that they date from the empire.
Each half of the double door weighs 8.5 tonnes, and rotates on pins set into the floor and the architrave above. An ingenious but laborious and little understood system allowed removal of the wooden architrave and replacement of the pins which tend to wear. In 1757, during an attempt to keep the door working, the whole thing fell, killing the foreman trying to remount it.
The right door was left totally blocked and the left door would open only partially. After two centuries and much careful study, using just soap (!) and specially-made plates to slightly lift the doors, the pins were replaced, the doors put back into their seats, and finally both could be opened and shut. It was 1998; the doors had not been fully opened for 241 years.

Below: The doors of the Pantheon, as they were in 1976, with the right door stuck shut. Photograph © Paula Chabot, from the VRoma Project.

The Eye to the Heavens

It is only once you are inside that the power of the Pantheon becomes clear: it is the huge dome and the oculus in its centre, even on days when rain is pouring through it.
In high antiquity, a writer such as Cassius Dio (155-235 AD), with no knowledge of the building’s history, was equally impressed by the oculus. He was one of many, including Michelangelo, who saw in this dome the mark of the divine.

Below: The oculus.

The dome was the largest in the world until its diametre of 43.3 metres (142 feet, 150 Roman feet) was surpassed by two metres when Filippo Brunelleschi completed the dome of Santa Maria del Fiore in Florence, in 1436. If we consider that the present dome was built around 100 AD, then it held the record for some 1900 years. It is one of the most studied, and even today we do not fully understand how it was built nor how it has remained intact so long, through earthquakes, settling, fires, and lightning strikes.

Hadrian Slept Here

Hadrian set up a magistrate’s bench where today the main altar is found, and here presided over cases, petitions, and the meetings of the Senate, perhaps dozing (and dreaming of exciting travels through the empire, far from the boring business of the capital).
The interesting thing about the altar is its form: it stands in an exedra, a structure used to project the voice, and typical not of temples but of civil buildings such as the basilica. Thus we have another clue that the Pantheon was transformed, when the south entrance was closed up, for use as an official hall.

Below: The main altar of the Pantheon.

Rodolfo Lanciani wrote that in 1828, when the old altar was being removed, columns engraved with the name Vibia Sabina, empress of Hadrian, were found here, although what became of them we do not know.

Which brings us to the use of the Pantheon first as a Christian church, then as a burial site for Rome’s greatest artists, and finally for modern Italy’s two kings. Of all the graves here, the tomb of Raphael is both the humblest and the proudest. His epitaph reads:

Ille hic est Raphael timuit quo sospite vinci
rerum magna parens et moriente mori.
Here is that Raphael, who while he had breath,
Mother Nature herself feared as an equal,
and when he lay dying, feared her own death.

The Baths of Nero

At this point, if you like, a short detour will take you to see two reminders that the emperor Nero, as well, built baths in this area, about 80 years after Agrippa’s.
Poor Nero couldn’t do anything right: in 62 AD he built a gymnasium at the northwest corner of the Pantheon, which immediately burned to the ground; he built luxurious new baths on the same site in 63, along with a bronze statue of himself which was immediately struck by lightning and blown to bits. However his baths were providential, since this area did not burn in the Great Fire of 64 AD and he was able to use them, along with the baths of Agrippa and the Pantheon, as temporary shelter for the thousands of homeless. In spite of his efforts to help the victims of the fire, his reputation did not fare any better; twenty-five years later, Martial wrote:

“Who was ever worse than Nero? Yet what can be better than Nero’s warm baths?”
—Martial, Epigrams, book 2, 48.

The baths are known as the Neronian-Alexandrian Baths because they were rebuilt in grandiose style in 227-229 AD by the emperor Severus Alexander. The huge amounts of stone recovered from their ruins date from that time.
The Salita dei Crescenzi, on your left as you exit the door of the Pantheon, marks the southern limit of Nero’s baths. The word Salita (rise, hill) is quite interesting, because any rise or hill in the ultra flat Campus Martius is suspicious – if there is a hill, it is because there is Stuff Under It. In this case the stuff is the mass of stone and brick which once made up the baths, and which can be found under and in all the building on either side of the Via della Dogana Vecchia from the Piazza di Sant’Eustachio up to the Piazza di San Luigi dei Francesi. All these houses are built literally in and atop the baths.

After a few metres up the Salita dei Crescenzi, you can turn left and proceed down the Via di Sant’Eustachio. Two pink granite columns along with a bit of the frieze found in front of the church of San Luigi dei Francesi in 1934 have been set up along the eastern wall of the church of Sant’Eustachio, in an area that was actually behind the baths (the entrance, at least in the third century, was on the north side). You notice we have gone downhill: we have left the ruins of the baths proper.

Below: Columns of Nero’s Baths found at the church of San Luigi dei Francesi.

Turn right at the church of Sant’Eustachio and walk across the Piazza di Sant’Eustachio, to reach the Via degli Staderari (there is usually a policeman on guard, since Palazzo Madama to the right houses the Italian Senate). A labrum, or bathtub, in pink Egyptian granite, converted to a fountain, adorns the Largo della Constituente. The labrum was found under Palazzo Madama and was set up as a fountain here in 1987.

Below: A bathtub, serving as a fountain.

Turn right up the Via della Dogana Vecchia and note how the street slopes upward again as we enter the central area of the baths.
Then take your first or second right back to the Piazza della Rotonda, and head for the fountain in the middle.

Isis and Serapis in the Campus Martius

Now that we have been thoroughly confused by the Pantheon, we can turn to a monument that is simpler to decipher, if harder to find, a temple that was vowed to destruction: the great Iseum, Isis Campensis, the temple of Isis in the Campus Martius.

We know where it stood not just from the rubble and bits of pieces scattered throughout the streets here, but also from its many mentions in ancient sources, for example by Juvenal, the satirist:

Si candida jusserit Io
Ibit ad Aegypti finem calidaque petitas
A Meroe portabit aquas ut spargat in aedem
Isidis antiquo quae proxima surgit Ovili.

If white Io [Isis] commands
She will go to the ends of hot Egypt
To fetch water from Meroe [island of the Nile]
To sprinkle in the temple of Isis
Which rises next to the Voting Pens of old.
— Juvenal, Book II, Satire 6, 527-529.

Isis had come to Rome quite early, through contact with the Greek cities to the south around 70 BC, but her cult at Rome really soared when Romans went to Egypt and Egypt became a Roman province. Isis brought with her Serapis, her consort, whose shrine stood in the same precinct, giving the whole complex the name Iseum et Serapeum. Isis and Serapis were the most human, and most Greek, of all the Egyptian gods (Serapis had been “invented” for the Egyptians by their Greek master Ptolemy I around 300 BC).

Below: Isis holding a sistrum (rattle, musical instrument), and Serapis wearing the Egyptian conical hat known as the “modius” (after the cup used to measure grain). Detail from the relief in the Louvre. Photograph by Marie-Lan Nguyen, 2007.

Looking at the fragmented remains of the Iseum, particularly the inscriptions on the obelisks, gives us a singular picture of Roman contact with Egypt. The obelisks are the work of a highly advanced, literate, centralised, imperialistic culture with a long, continuous history stretching back a thousand years, produced at a time when Rome was nothing but mud huts and sheepfolds.

The first fragment of the Iseum we come across is against the wall of brick around the portico of the Pantheon, on your left as you stand in the portico with the main door of the Pantheon to your back. It is a corner of the architrave that we can date from Domitian’s restoration (~85 AD) since the flower motifs are exactly the same as those on the Arch of Titus (arch on the Via Sacra built by Domitian to honour his brother Titus). The block was brought here along with other spolia sometime before the 8th century and used as a step in the stairs which once led from the piazza to the portico. That staircase was found and the blocks used as steps were left here along the wall in 1874.

Below: A bit of frieze from the Iseum, alongside the portico of the Pantheon.

The face of the frieze shows lionesses drinking from kraters (large vases), and the corner shows two falcons, crowned by the double crown of Upper and Lower Egypt. Between them is a caduceus.

The second remnant we come across is the obelisk at the centre of the fountain in front of the Pantheon. This is the Obelisk of Macuteo, brought here in 1711 when pope Clement XI Albani completed his restorations of the Pantheon. Although it honours the pharaoh Ramesses II, it takes its name from the Church of San Macuto, situated at the north-eastern entrance to the Iseum, which we will come across shortly.

Below: The 1290 BC Obelisk of Ramesses II atop the 1575 AD fountain of Giacomo della Porta, put together in 1711.

To find more pieces of the Iseum, turn back and walk along the wall of the Pantheon on the Via della Minerva to the Piazza della Minerva. There we find another obelisk from the Iseum, supported by a slightly odd-looking elephant, the Pulcino. This is the Obelisk of the Minerva, dated to about 580 BC, and brought to Rome from Sais, a city in the Nile Delta.

At the corner of the Church of Santa Maria Sopra Minerva, turn left onto the Via del Piè di Marmo, and walk about 150 metres (about 500 ft.) ahead, past the Via del Gesù (an oddly-straight street built along the eastern portico of the Voting-Pens, the Porticus Meleagri). At the corner of the Via di Santo Stefano del Cacco, you can see a giant foot sitting on a high pedestal.

Below: The left foot of Isis.

This one piece is thought to be from a cult statue of Isis, perhaps belonging to the large statue of Isis known as Madama Lucrezia in front of the Basilica of San Marco at Piazza Venezia. Exactly when the foot was found is not known, but it stood on Via del Piè di Marmo until 1878, when it was moved to this corner to make room for the passage of the funeral procession of Italian king Victor Emmanuel II, who was to be buried in the Pantheon.

Continue on the Via di Santo Stefano del Cacco, past the tiny church of Santo Stefano del Cacco, built directly within the sanctuary of Serapis. Between the Via di Santo Stefano del Cacco and the Piazza del Collegio Romano is the church of Santa Marta, where the temple of Minerva Chalcidica stood.

Below: Remains of the Iseum and Minerva Chalcidica mapped onto present-day streets.

Santo Stefano del Cacco was rich in relics of the temple. It got its name from a statue of the god Thot in the form of a baboon, which Romans called a “cacco” (from macaco, “baboon”).

Below: A “cacco” discovered in the dromos of the Iseum in 1883.

Flavio Vacca, in his Memorie di varie antichità trovate in diversi luoghi della città di Roma (“Memories of Various Antiquities Found in Different Places in Rome”, 1594) recalls seeing both the baboon and two basalt lions in front of the church. The lions are now on the Cordata (Great Stairway) up to Capitol, where they serve as fountains.

Below: One of the lions of the Iseum, now at the foot of the grand staircase to the Capitol.

Where the Via di Santo Stefano del Cacco reaches a small piazza, turn left onto Piazza Grazioli, and look up to the cornice of Palazzo Grazioli (on the south side of the Piazza), above a funeral monument commemorating Riccardo Grazioli Lante della Rovere, killed in 1914. There stands a tiny statue of a cat which also came from the Iseum, and which has given its name to the Via della Gatta. Its eyes, Romans say, are fixed on the treasure it is guarding, but where that treasure might be has yet to be discovered. The “gatta” was placed here when this back portion of Palazzo Grazioli was added in 1863-1874.

Below: The tiny cat from the Iseum, peering at her treasure.

Now we walk up the Via della Gatta, another oddly-straight street which runs along what was once the eastern portico of the Divorum, out onto the Piazza del Collegio Romano. Just to our left is the church of Santa Marta, built over the remains of the temple of Minerva Chalcidica.

Then cross the Piazza del Collegio Romano and continue northward on the Via di Sant’Ignazio, which roughly corresponds to the eastern limit of the Iseum. At the end of the street we stand in front of the tiny church of San Macuto, whose roof is decorated with small obelisks, also remains from the Iseum (the large obelisk now on the Piazza del Pantheon stood here as we know until 1711).

Below: The five little obelisks of the Church of San Macuto.

At the centre of the Piazza di Sant’Ignazio, take the tortuous Via de’ Burrò, which winds behind the 18th-century houses where the French administrators of Rome (1778-1814) had their offices (bureaux). Here, we are behind other offices  – Rome’s Chamber of Commerce and its tiny Stock Exchange, housed as we soon shall see, in a most prestigious building.

The Imperial Cult

Puto deus fio
I think I’m turning into a god
–Vespasian, as he lay dying (from Suetonius, The Life of Vespasian).

As you turn the corner onto the Piazza di Pietra, you see a building that does indeed look somewhat like the stock exchanges of New York and especially Paris, with the slight difference that these columns belong to the temple of the Divine Hadrian and happen to be 1800 years old.

Below: The Hadrianeum, the temple to the divinised Hadrian.

The temple of Hadrian was a monument to the empire, to the Roman peace, and to the curious custom of those first emperors who chose their successors not among their children but among the most able men of the realm. And those grateful (and crafty) successors deified their benefactors, angling for the respect and good will of the Roman people. Not everyone was credulous, though, and we have at least one text, The Pumpkinification of Claudius, to prove it.

Hadrian spent at least half of his reign travelling around the empire and consolidating its borders. The temple of the Divine Hadrian was thus appropriately decorated with reliefs of the Roman provinces, personified as women.

Below: The province of Phrygia (or Bithynia) in the Hadrianeum, now in the National Archaeological Museum of Naples. Photograph © 2011, Marie-Lan Nguyen.

Hadrian’s temple was in ruins by the fifth century, and the memory of whom it was dedicated to was lost. Bit by bit it was stripped of its metal and marble. But it is both fireproof and enormously strong: the temple’s foundations are a series of barrel-vaults, and the cella itself is a single barrel-vault, 18 metres (59 ft.) in diameter, built on the same “lighter-as-you-go-up” principle as the Pantheon. Thus even the metal and stone robbers did not manage to reduce it to utter ruins, and pope Innocent XII Pignatelli was able to “fix it up” to use as a customs house in 1695.

Along the north side of the temple, the podium has been exposed, revealing the action of the annual Tiber floods which raised the piazza 4 metres (12 ft.) above imperial street level.

A Divine Mother-in-Law

Continue past the Temple of Hadrian down the Via dei Pastini and take your second right onto the tiny Vicolo della Spada di Orlando.

Here we are within a temple that was the twin of Hadrian’s (or rather Hadrian’s temple was the twin of this one, as this temple was about 30 years older): the Temple of the Divine Matidia. Your jaw may drop, but Salonina Matidia was Hadrian’s mother-in-law, and it was Hadrian who deified her. Matidia’s temple has however been completely destroyed. Its only remains are seven columns found under houses and streets here and the low wall along the Vicolo della Spada di Orlando.

Below: The cracked column from Matidia’s temple at 72 Via della Spada di Orlando, split by Roland’s sword Durendal (or so they say).

As you have noted, this area was thick with public architecture by the high empire. To reach the next major monument, proceed to the top of the Vicolo della Spada di Orlando onto the Piazza Capranica and take a right past the church of Santa Maria in Aquiro onto the Via in Aquiro, and then left, up the slight rise, to Montecitorio, the southern limit of the area where Octavian erected his most famous monuments.

The Clock That Never Struck

As you approach Montecitorio (or “Citation Hill” as it might be called), you walk up a slight incline. Here we have once again a Highly Suspicious hill in the flat Campus Martius. In the case of Montecitorio though, the hill is not the result of destruction, but a deliberate raising of the ground level, first of all to repair Octavian’s Clock (imagine needing a small hill just to fix a clock).
But this wasn’t just any clock. It was a massive sundial, and its needle (or gnomon) was the huge obelisk that stands today at the centre of the Piazza di Montecitorio. It was not originally at this spot, but stood at the very top of this little hill, at the western edge of Palazzo Montecitorio, the Italian Parliament.

Below: The Obelisk of Piazza Montecitorio, once the gnomon of the Horologium Augusti, Octavian’s Sundial.

Pliny, writing in the 70s AD, describes the sundial for us, and notably says it had been off for the past 30 years or more. From Pliny’s text, it is reasonable to think that the obelisk was not a solar clock, if it ever was: all that was expected of it was to tell the time once a day, at noon, when the shadow of its crowning brass globe passed over a line indicating the seasons (the same method used by Bianchini’s Meridian in the church of Santa Maria degli Angeli at Piazza della Repubblica – nothing new under the sun). Thus its vocation was more that of a calendar, for which Romans had a dire need.

Below: The Meridian Line of Octavian’s Sundial, found under the house at number 48 Via del Campo Marzio (once a stable).

A look at the meridian line gives us the odd suspicion that the Romans might have copied it from somewhere else in the Greek world (although the use of Greek is not odd, as Greek was the language of science). The portion of the line under the house at 48 Via del Campo Marzio shows summer, which began, according to the meridian, in May when Taurus was visible, and ended “at the tail of Leo”, in early September, when the summer winds of the Aegean Sea (Greece) cease. This meridian lies 2.25 m (7.4 ft.) above the original foundations, and bears additional lines showing that days were added to correct it.

Below: Sketch of Octavian’s Meridian under the house at number 48 Via del Campo Marzio. The portion shown is summer.

A team of German archaeologists found the meridian in 1979 on the north-western edge of Piazza del Parlamento, the area behind the Italian Parliament, not far from where the Ara Pacis was found in the 16th century. By putting together the data from their soundings and the depth of the Ara Pacis found under Palazzo Fiano at the corner of Piazza San Lorenzo in Lucina, they concluded that the obelisk and meridian had been raised at least three times: in approximately 75 AD, 86-88 AD, and 120 AD.

Below: The findspot of the Horologium and its present position, mapped onto modern streets.

By the time of the emperor Caracalla (~200 AD), the whole area was urbanised with apartment houses built around the clock area. The obelisk was still standing in 800 AD, although the base was 5 metres below street level. It toppled, probably in an earthquake (there was a big one in 849), and was forgotten. It was found again in 1463, when building a house, but not being easily extracted was left in place until 1748, when pope Benedict XIV Lambertini had it excavated. In 1792, Pope Pius VI Braschi had it repaired with red granite from the Column of Antoninus Pius and set up where we see it today.

Below: The broken pieces of the obelisk of the Horologium Augusti were found under this house on the Piazza del Parlamento, to the left of the “Antique Clock” shop. An inscription over the door at number 3 records the find.

Even though the resurrected obelisk was never used as a sundial again, there is one that was, and that is the old obelisk of Nero’s Circus, in Saint Peter’s Square. In 1817, round markers and a meridian line were placed in the paving between the obelisk and the fountain just north of it. The tip of the obelisk’s shadow marks the date and noon as it passes over this line.

Below: One of the meridian markers in St. Peter’s Square.

The Column of Marcus Aurelius

“Like leaves are the children of men, scattered by the wind.”
– The Iliad, Book VI, quoted in the Meditations of Marcus Aurelius.

189 years after the emperor Augustus set up his clock, the emperor Marcus Aurelius died. Marcus was the last of the “Five Good Emperors”, a man raised to rule the empire wisely, a Stoic philosopher whose Meditations is read with admiration even today. He died in the field, at Vienna. The Senate deified him and voted him a temple and the spiral column which still stands today here in Piazza Colonna, a tribute which contradicts everything the austere Marcus believed in.

Below: The emperor Marcus Aurelius. Detail of the equestrian statue at the Capitol.

In spite of his love of peace, Marcus Aurelius was never to know it. The Parthians (Persians) threatened the empire as soon as he assumed power. But there was even worse to come during his reign: his soldiers brought back smallpox from Parthia, and the Goths were on the move.

Bearing right past the obelisk, walk down the slight incline to Piazza Colonna, leaving on your right Palazzo Wedekind, which stands on the spot where we are fairly certain the Temple to the Divinised Marcus Aurelius and Faustina the Younger once stood. At the centre of the piazza is the celebrated column, wound around with scenes from the Marcomannic wars.

Below: The Column of Marcus Aurelius.

The column is a deliberate imitation of Trajan’s Column, making a parallel between Marcus Aurelius and his greatly-respected predecessor. Pope Sixtus V Peretti, when restoring both columns around 1589, placed twin statues of Peter and Paul atop them.

Nothing Easy

The Parthian war (161-166) was largely successful, except for two things: legions were moved east, exposing the northern frontier, and smallpox was killing large numbers of Roman troops. The Germanic tribes allied under Ballomar knew it, and they attacked.
So did the Germanic Quadi, east of Carnuntum (Austria and Slovakia). So did the Iranian-speaking, nomadic Iazyges, in the Tisza River plain (Hungary and Serbia). It was a regular field day.

Marcus Aurelius raised new legions and took them north, and with method, put things back in order: he called Galen to deal with smallpox, he re-occupied the Germanic territories, forced the Quadi to surrender, and brought the Iazyges back into the empire.
When he needed a miracle, he got it. Two of them are shown on the column: the Lightning Miracle, in which a Quadi siege machine is struck by lightning at the emperor’s behest, and the Rain Miracle.

Below: The Rain Miracle.

The Rain Miracle is an episode of the Germanic wars that impressed many ancient writers. The Roman army was hemmed in, they wrote, by a vastly superior number of Quadi who were trying to force them to surrender by depriving them of water. The emperor prayed for a miracle, and a Water God (looking a bit like Old Man Tiber) immediately gratified him with a deluge:

“Some held out their shields and some their helmets to catch it, and they not only took deep draughts themselves but also gave their horses to drink.”
Cassius Dio, Roman History, Book 72.

The Water God was thoughtful enough to drown the enemy too, so the Romans carried the day. If you have sharp eyes you can easily find the Rain Miracle: it is on the third band on the eastern side, the side facing Via del Corso, just above the inscription commemorating the restoration by pope Sixtus V.

The damaged scene of the Lightning Miracle is harder to pick out: it is on the north side, facing Palazzo Chigi, on the second band above the inscription Triumphalis et Sacra Nunc Sum ... (“Triumphant and sacred am I now”).

Below: The Lightning Miracle.

And if you have very sharp eyes, you can pick out yet another interesting scene: Winged Victory writing on a shield, which separates the two campaigns, exactly as on Trajan’s column. This scene is again on the eastern (main) side facing Via del Corso, on the tenth band from the bottom, at about midway up. It is here you can see how the whole top of the column has shifted, the drums above being 10.4 cm (4.1 in.) to the right. This is especially clear from the bottom of Victory’s wing, which she seems to have left behind her.

Below: Winged Victory, between two drums which are no longer aligned. Above her to the left, captives are beheaded.

The drums shifted because medieval metal thieves stole all the pins that held them together, letting them jiggle about at every earthquake. Pope Sixtus V Peretti had them all pinned back together when he restored the column in 1589, before things got any worse. If you look closely, you can see long metal bands in spots where they were particularly wobbly.

You may now give a little gasp that the whole thing is still there. Because the column stands as it has always stood: unlike the obelisks we have seen, it has never fallen or been propped up or moved. The base is the original, with about a third of its height buried underground. The Column of Marcus Aurelius has seen Rome fall and rise and change around it, shaken by earthquakes, blackened by soot and eaten away by motor exhaust, yet is valiantly still here to tell us its stories.

And here ends our walk.
To the next walk: Buried by the River, or the Tombs of Two Emperors.
About...

The Altar of Mars in the Campus Martius: This altar is fleetingly mentioned by Livy, Festus, and Suetonius. We know it was standing at least in 443 BC, and was associated with the census. It stood (perhaps) directly in the Villa Publica, where the Roman population was counted by the censors and men of military age were assigned to their legions. To the east was the Servian Wall and the Porta Fontinalis (Piazza Venezia). Multi-level ruins found under the Via del Plebiscito in 1925 are thought to be its remains.   ← Back

Marshland in the Campus Martius: Agrippa converted a marsh known as Palus caprae, the “goat swamp”, to make his lake, which remained lower than the surrounding areas even after it was silted in and built over in centuries to come. Hence the name “Alla Valle” for the area between Pompey’s Theatre and the Baths of Nero (between the modern Corso Vittorio and Piazza di Sant’Eustachio). A portion of the canal draining the lake toward the Tiber was discovered under the church of Sant’Andrea della Valle in 1949.   ← Back

Agrippa’s Property: The land owned by Agrippa on the Campus Martius was previously the property of Mark Antony, whom Agrippa defeated during the civil wars at Actium in 31 BC. Before Mark Antony, the same land had belonged to Pompey, likewise defeated during the civil wars by Julius Caesar at Pharsalus in 48 BC.   ← Back

Arco della Ciambella: The ruins jutting out of the buildings on Via dell’Arco della Ciambella are part of a circular domed structure belonging to Agrippa’s baths. A marble block bearing the word “Agrippa” was unearthed here in 1888; fragment 38 of the Severan Marble Plan, labelled “Thermae Agrippae” shows a form for this room and surrounding buildings (some found in various excavations) that corresponds to what we see today.
These remains are composed of brick-faced cement, once covered by a dome 25 metres in diameter. About half of the circular hall has survived, extending into the buildings on the northern side of the Via dell’Arco della Ciambella.

How this area might have gotten the name “alla Ciambella” is retold in the 1594 memoirs of sculptor Flaminio Vacca. It starts with an avid collector, cardinal Andrea della Valle (1463-1534), of the della Valle family which took its name from its seat in the low-lying area once the Lake of Agrippa in the Campus Martius. The cardinal employed Flaminio’s father and other men to search for treasure in the Baths of Agrippa, where they found a sculpture in bronze depicting the Civic Crown. Since the crown looked to them like the ciambella or “doughnut” that was used to cushion a load carried on the head, the famous crown got the name of “ciambella”, and being used as the sign of a tavern there, the whole neighbourhood became known as “Alla Ciambella”.

Below: Augustus wearing a “doughnut”, the Civic Crown. Photograph of the plaster cast in the Ara Pacis, © Giovanni Dall’Orto, 2008.

However it’s up to you to decide whether it was the civic crown or just the round room that gave the area its name, since prior to the 1500s the ruins were known as the Tondo (“round thing”), Rotulo (“roll”) and also the Torrione (“big tower”).

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Flaminio Vacca: 1538-1605. A Roman sculptor, he is buried in the Pantheon, having been honoured with membership in the Accademia dei Virtuosi al Pantheon. Vacca’s memoirs are one of the main sources for details about the 16th-century rediscovery of ancient Rome.
← Back to the Pantheon
← Back to Pirro Ligorio, the Baths of Diocletian

The Civic Crown: It was actually a military honour, a simple crown made of oak leaves, given for having saved the life of fellow citizens. Once awarded, it was to be worn at every public occasion, and gave its wearer certain rights and privileges, such as a seat in the Senate.
The award of the Civic Crown to Augustus in 27 BC for having ended civil war and thus having saved the lives of his fellow citizens marks the beginning of the principate, the early imperial period.   ← Back

The Saepta Iulia: A saeptum (or ovile as the voting pens were first called) was a sheep fold or corral, that is a set of fences through which sheep proceeded in orderly lines to be shorn or milked or whatever. In the plural it designated the spot at Rome where men voted, lined up in their voting groups or “centuries”.
The Saepta were very old indeed: Roman tradition placed their first use in the reign of king Servius Tullius (~578–535 BC). Julius Caesar planned to rebuild them in 54 BC, but did not get around to doing it. Agrippa, that great builder, finished them in 26 BC, and dedicated the whole complex to the Julian family to honour his friend Octavian.
The Saepta occupied a huge space between the hecatostylum (Porticus Pompei) on the south, the Baths of Agrippa (the Pantheon) on the west and the Iseum on the east, the whole surrounded by porticos, along which now run the unusually-straight modern streets Via del Plebiscito, Via dei Cestari, Via del Seminario and Via del Gesù.
On the southern side stood the Diribitorium (from diribere, “to sort voting tablets”), a building where the votes were counted. The Diribitorium was famous in ancient Rome for the extraordinary beams that supported the roof, 100 Roman feet long (29.6 m or 97.11 ft.). One of those beams was left in the Saepta for people to admire.
The portion of the Saepta visible along the Pantheon belonged to the west portico, called either the Porticus Agrippiana or the Porticus Argonautarum, since it was apparently decorated with scenes from Jason and the Argonauts.
Since the voting-pens no longer had a function under the empire, the space was used for shows, public display of artworks, and shops.   ← Back

Caldarium or Calidarium: This was the heated room in the baths, also known as a vaporarium or sudatorium. It was also sometimes called a laconicum or laconium from the word “Laconia”, or “Lacedaemonia”, the region inhabited by the Spartans, who were said to have originated the sweat bath.   ← Back

The Canonical Form of the Hot Room: In De Architectura, book V, chapter 10, 5, Vitruvius prescribes a hemispherical form for the hot room, its height being equal to its width, and topped by a dome such that heat and vapour are evenly distributed along the walls. At the apex of the dome an opening is covered by a round bronze shield suspended on chains. This bronze cover can then be raised or lowered to regulate the temperature within.
Baths should also face west, or barring that, south, since baths were taken in the afternoon.
An oddity of the Pantheon is that there are hooks at the base of the oculus.   ← Back

The Fire of 80 AD or the Fire of Titus: Emperor Titus was in Campania inspecting the damage done by the eruption of Vesuvius in 79 AD when a great fire broke out in Rome. According to Cassius Dio, it destroyed huge parts of the Campus Martius and the Capitol:

“the temple of Serapis, the temple of Isis, the Saepta, the temple of Neptune, the Baths of Agrippa, the Pantheon, the Diribitorium, the theatre of Balbus, the stage building of Pompey’s theatre, the Octavian buildings together with their books, and the temple of Jupiter Capitolinus with their surrounding temples. Hence the disaster seemed to be not of human but of divine origin; for anyone can estimate, from the list of buildings that I have given, how many others must have been destroyed.”
–Cassius Dio, The Roman History, Book LXVI.

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The Debate on the Pantheon: To this very day archaeologists are not completely certain about the Pantheon. Some believe its form to be essentially unchanged since Agrippa’s time (25 BC), and that it may have developed from the caldarium, simply because it is built in the canonical form (a hemispherical domed structure with an opening at its summit) and that it is so close to the rest of the baths. Moreover, the architect who built the Pantheon for Agrippa, Lucius Cocceius Auctus, was a native of Cumae, near Baia, where a similar concrete dome with an oculus topped a caldarium.
The most widely accepted vision today is that the rotunda was built under the emperor Hadrian, mainly because of brickstamps which date it to his time, and because of doubts that so large and stable a dome could have been built in 25 BC (although so large and stable a dome, in unreinforced concrete, cannot be built even today). Another speculation is that the area of the rotunda was an open, circular space in Agrippa’s day, flanked by the rectangular Basilica of Neptune on the south and a rectangular Pantheon on the north.
But as you can see, none of these ideas are really incompatible, particularly since the Baths of Agrippa and the Pantheon repeatedly burned, were struck by lightning, and damaged by tremors and floods. We know of restorations under the emperors Domitian (~81-96 AD), Trajan (~110-117 AD), Hadrian (~125-138 AD), Antoninus Pius (138-161 AD), and Septimius Severus (202 AD).
Thus really nothing is certain about the Pantheon before about 120 AD, not even its name. And the front portico, its inscription, and the strange double pediment do nothing to clarify any of the mysteries. The best guess is that it was perhaps a temple consecrated to the Julian dynasty and their gods both mortal (Julius Caesar and Octavian) and immortal (Venus).
We do know that the rotunda was constructed or re-constructed sometime between 90 and 140 AD, after it “burnt by lightning” as 3rd and 4th-century historians put it. By 90 AD, there was a precedent for a dome-with-oculus used not for a bath but just to top a room: the Octagonal Room of Nero’s Golden House (~66 AD). And although the Octagonal Room had been buried under Trajan’s baths by 104 AD, there was one architect who would have seen it: Apollodorus of Damascus, who worked for both Trajan and Hadrian. Moreover, in Trajan’s Baths, Apollodorus built coffered, tapered half-domes quite similar to the full dome of the Pantheon.

Below: Remains of the coffered half-dome of Trajan’s Baths in the Park of Colle Oppio.

Thus, some theorists maintain that the dome of the Pantheon as well was the work of Apollodorus.
Still another theory exists as to the reason for the oculus: since the Pantheon was a temple to the Iulii, the architect (whoever he was) made a conscious effort to associate the Julians, either Julius Caesar or Octavian or both, with the legend that Romulus had ascended to the sky at the Palus Caprus, the goat-marsh, which just happened to be here, on Agrippa’s property. To make this link in people’s minds, he made sure you could see the sky through a nice big hole at the top of the temple.
← Back to the Campus Martius
← Back to the Baths of Diocletian

Early concrete dome: The “Temple of Mercury” at Baiae is a concrete dome with an oculus at centre, over a caldarium that used natural hot springs. The dome is 21.5 metres (71 ft.) in diameter, about half the size of the dome of the Pantheon. It was built in the 1st century BC, predating the Pantheon.   ← Back

Santa Maria ad Martyres: In 609 AD the Byzantine emperor Phocas (reign 602-610 AD), nominally the sovereign of Rome where Pope Boniface IV (pontificate 608-615) was de facto ruler, ceded the Pantheon to the pope for use as a church.
The name ad Martyres, “at the place of the martyrs”, refers to the numerous relics pope Boniface had dug out of the catacombs and placed here. This practice, and perhaps admiration for the “divine” Pantheon (as Michelangelo put it), gave rise to the burial here of gifted men, such as Raphael Sanzio, Arcangelo Corelli, Baldassare Peruzzi, and other honoured artists of Renaissance Rome.
After Italian unification the kings of Italy were also buried here: Victor Emmanuel II (died 1878, buried here in 1884), Umberto I (died 1900, buried here 1904), and queen Margherita in 1926.   ← Back

The Importance of the Pantheon: The Pantheon is the best preserved of all classical buildings and one of the oldest, if we believe that at least some of its surviving parts were built by Agrippa around 25 BC. It became the model for many many other buildings both in the ancient and the modern world: one need only to think of the 18th-century Parisian Pantheon, the British Museum Reading Room, the American Congress building, the Sankt-Hedwigs-Kathedrale in Berlin: the list of libraries, churches, and civic buildings emulating the design of the Pantheon is endless.
As much as its form, the techniques used in its construction continue to inspire and puzzle engineers and architects.   ← Back

Pediment inscription: Under the large inscription is a much smaller and fainter one:

IMP CAES L SEPTIMIUS SEVERUS ET IMP M AURELIUS ANTONINUS PANTHEUM VETUSTATE CORRUPTUM CUM OMNI CULTU RESTITUERUNT
“Emperor Septimius Severus and Emperor Marcus Aurelius Antoninus (Caracalla) restored the worn-out Pantheum to elegance”

The restoration of the Severans must have been very limited, since no stonework or bricks from their time (193-217 AD) have been found.   ← Back

The Construction of the Pantheon: Its incredible stability starts unsurprisingly with the extremely thick wall of the cylindrical drum which supports the dome. The drum wall is 6.4 metres (21 feet, 40 Roman feet) thick, but is not solid masonry: there are 16 voids in the wall, comprised of eight load-bearing arched barrel vaults and eight blind niches at the lowest level, with smaller cavities above. The foundations are even wider than the wall: a 10-meter wide double ring made of layers of lime and pozzolan concrete, extremely hard and waterproof.
The dome is made of unreinforced concrete: there is no metal in it at all. It is a series of seven concentric rings, each decreasing in width, placed one atop the other in a construction technique known as “corbelling”. Each ring is itself made of concrete laid down in layers 20 cm (7.9 inches) thick, one layer at a time. And each successive ring is smaller and lighter: the dome is 5.9 meters (19.4 ft.) thick at the bottom ring, while the smooth top ring tapers off to 1.5 metres (5 ft.) at the oculus. The bottom rings are made of pozzolan and lime concrete, with heavy tuff and brick mixed in; the top rings are concrete mixed with light tuff and porous volcanic stone. The secret of the dome’s stability would appear to lie in the concrete: Roman concrete cured very very slowly, becoming harder and harder as time passed.
Each ring is lined on the inside with a band of 28 coffers. The coffers are not structural: they were there so the builders had something to nail the bronze covering onto, and are hollow to keep the dome light.
← Back to the Dome and Oculus
← Back to the Importance of the Pantheon

Pozzolan or pozzolana: A volcanic pumice or ash which takes its name from Pozzuoli (near Naples) where it is especially abundant.
Roman concrete was a mixture of burnt limestone and pozzolan, in ratios that were given by Vitruvius in De Architectura: 1 part lime to 3 parts pozzolan for ordinary concrete, 1 part lime to 2 parts pozzolan for marine concrete, which sets in salt water.
Roman Pozzolan concrete was made apparently with very little water and (as Vitruvius wrote) was tamped with a special tool into whatever stone it was binding. It took a very long time to harden and cure, but once rock-hard, possessed a strength and flexibility that actually increased with time (whereas many modern cements start to crumble after 100 years).   ← Back

The Name of the Pantheon: It seems the word “Pantheon”, from the Greek “of all the gods”, was a nickname for this building, since ancient writers such as Cassius Dio and Macrobius both refer to it as “the so-called Pantheon” and “the temple they call the Pantheon”. In Hellenistic culture, temples to all the gods or to the twelve great gods were called Pantheon and Dodekatheon. Since Agrippa’s temple was dedicated it seems more to the deified Julians than to all the gods, Romans may have felt that it did not quite deserve the name “Pantheon”.
In any case it had this name already on 12 January 59 AD, because we possess an inscription telling us that the Arval Brethren met in Pantheum on that day.
Cassius Dio, writing in the early 3rd century, personally thought the name came from the oculus, which looked up to the heavens, but also wrote that the name may have come from the many statues of different gods that adorned it, such as the statues of Mars and Venus.
← Back to the Pantheon

The Baths of Agrippa: They are very well documented in ancient sources, mentioned by Pliny the Elder, Martial, Seneca, Cassius Dio, and numerous other works and inscriptions. They were built in 19 BC, once the Aqua Virgo aqueduct which supplied them with water was completed. In 12 BC Agrippa died and left them to the Roman people, making them the first public baths in Rome.
We know from ancient sources that a structure called the “laconicum” was built much earlier, in ~27-25 BC, at the same time as the Pantheon. What exactly this “laconicum” was is quite confusing: the word generally meant a sweat bath, after Spartan Laconia where it originated, but could also have been an open exercise area.
Agrippa’s baths were renowned for their artworks, described by Pliny the Elder in his Naturalis Historia. The caldarium was adorned with marbles and wax paintings, and the entrance and garden boasted famous statues such as the Apoxyomenos and the Lion, both the work of the sculptor Lysippos.
The baths functioned until the 5th century. By the 8th century their ruins had become a quarry for stone.   ← Back

Lysippos: Lysippos, born in about 390 BC near Corinth, worked for Alexander the Great. His statues in bronze and marble became legendary and were copied throughout the ancient world. His most famous statues are known from Roman copies: the Farnese Hercules in the Archaeological Museum of Naples, the Apoxyomenos (“The Scraper”) in the Vatican, “Eros Stringing the Bow” in the Capitoline Museums.   ← Back

Pontificia Accademia dei Virtuosi al Pantheon: The Pontifical Academy of Artists at the Pantheon was founded in 1543. Membership in it is honorary, a papal nomination for exceptional talent. In the 17th and 18th centuries its members exhibited their work in the portico of the Pantheon.
← Back to Flaminio Vacca, the Pantheon
← Back to Pirro Ligorio, the Baths of Diocletian

Raphael: Raffaello Sanzio of Urbino, one of the great masters of the Renaissance, died at the age of 37 in 1520.
According to the “Life of Raphael da Urbino” in Giorgio Vasari’s Lives of the Most Excellent Painters, Sculptors, and Architects (1568), Raphael returned home one day in April 1520 stricken with fever, after indulging, as he was wont to do, in “piaceri amorosi” (we suppose with his lifelong mistress and model Margherita Luti, La Fornarina or “Little Baker”). He died several days later, after lucidly putting his affairs in order, being speeded on his way by bloodletting.
In his will he left a sum of money for the restoration of an edicola (small niche that contains a painting or statue) in the Pantheon, along with his wish to be buried there. Lorenzetto Lotto, one of his pupils, executed a statue for his tomb, the Madonna del Sasso, in the second edicola to the left of the main altar.
The memory of where Raphael was buried was then lost: he was said to lie in the Chapel of Urbino in Santa Maria Sopra Minerva, while a skull in the Church of Saints Luca and Martina, the artists’ church near the Forum, was said to be Raphael’s.
In 1833 the Pontifical Academy of Artists at the Pantheon set out to find the tomb, fully expecting to find a skeleton without a skull or perhaps nothing at all. The search for Raphael’s remains started on September 9, using the information in Lorenzetto Lotto’s biography and the “Life of Raphael da Urbino” by Vasari. As archaeologist Rodolfo Lanciani recounted, it took five days to remove the niche containing the Madonna del Sasso and dig down into the crypt below it, when

“At noon of September 14, 1833, the last stone was removed, and the excited assembly beheld for the first time the remains of the “divine painter”. [...] At 2.25 P.M., Gaspare Servi announced the discovery of the skull, the leading feature of which was a double set of strong, healthy, shining teeth.”
–Rodolfo Lanciani, Ruins and Excavations of Ancient Rome, 1897.

The remains of Raphael were then placed in a coffin in public view below the Madonna del Sasso.   ← Back

Neronian-Alexandrian Baths: The baths are remembered in ancient sources for their luxury. Like the Baths of Caracalla, they had a network of underground service tunnels. They were very popular and thus crowded; Severus Alexander extended their opening hours into the night. They remained in use into the 5th century.
Their ruins run from the church of San Luigi dei Francesi, built in the gymnasium on the northwest corner, to the Senate, Palazzo Madama, over the hot baths on the southwest corner, to the corner of the Piazza della Rotonda on the southeast corner, and Palazzo Rondanini on the northeast corner.
The only sure remains from Nero’s time are a flooring under the church of San Luigi dei Francesi and a bathtub recovered from Palazzo Madama.

Below: The Baths of Nero mapped onto modern streets.

Since the water from the Aqua Virgo aqueduct was insufficient for these new baths, Severus Alexander built a new aqueduct to supply them, the Aqua Alexandrina, of which there are many remains still standing.

Below: Arches of the Aqua Alexandrina at the Fosso di Centocelle, in the eastern part of Rome.

From the 15th century to the present, mosaics, granite basins and columns, and bits of the frieze have been extracted from the ruins. Two columns in pink Egyptian granite from Nero’s baths were mounted at the northeast corner of the Pantheon when the portico was restored in the 17th century.   ← Back

Temple of Isis in the Campus Martius: When exactly it was first constructed is unknown, but Julius Caesar, who as we know had a soft spot in his heart for the Egyptian queen Cleopatra, may have had a hand in it, directly or indirectly. In any case, the triumvirate of 43 BC (Octavian, Mark Antony, and Lepidus) voted a temple to Isis and Serapis, probably the temple in the Campus Martius, and possibly as a gesture meant to enlist Cleopatra on their side in the pursuit of Caesar’s assassins. But this is just a guess.
The emperor Domitian restored the Iseum after the fire of 80, and most of the remains scattered far and wide come from this 1st-century complex. It was adorned with at least ten obelisks, large and small, including the Obelisk of Domitian, today the centrepiece of the Fountain of the Four Rivers at Piazza Navona.
← Back to the Campus Martius
← Back to the Baths of Diocletian

Cleopatra VII of Egypt: Cleopatra hardly needs any introduction: she is perhaps the most famous woman of the ancient world, even in her own time.
She was the 17th and last monarch of the Greek Ptolemaic dynasty which ruled Egypt from 305 to 30 BC. She was the mistress and ally of both Julius Cesar and Mark Antony, and bore children to both. Ancient writers agree on her beauty, wit, daring and intelligence, and abound with stories to prove it. Her adventures start when, at age 21, exiled from Alexandria by her brother Ptolemy XIII, she nonetheless manages to meet Julius Caesar:

[she] embarked in a little skiff and landed at the palace when it was already getting dark. To escape notice, she stretched herself inside a bedroll, and Apollodorus tied the bedroll up with cord and carried it inside [...]
–Plutarch, “Life of Caesar”, in The Parallel Lives

We can imagine Caesar’s surprise upon unrolling the bedding. He was 51 at the time.

In the “Life of Antony” we read:

When she spoke, it was a pleasure merely to hear the sound of her voice, with which, like an instrument of many strings, she could play in any language she wished. There were few barbarians (non-Greek speakers) for whom she used an interpreter; she spoke without help to the Ethiopians, Troglodytes (people of the coast), Hebrews, Arabs, Syrians, Medes, and Parthians. They say she knew several other languages as well [...]
–Plutarch, “Life of Antony”, in The Parallel Lives

And her pranks on Mark Antony are also legendary. Apart from serving him her pearl at dinner, she bested him at fishing:

One day when fishing and catching nothing, Mark Antony secretly ordered his servants to dive and put previously-caught fish on his hook. But the queen was not fooled: she called for a new fishing party on the morrow, summoning friends to witness Antony’s prowess. When he cast his line, she had her divers fix a salted Pontus herring to his hook [...]

When captured by Octavian in 30 BC, after the final defeat of Mark Antony, she famously committed suicide by allowing herself to be bitten by an asp rather than be paraded in his triumph.   ← Back

The Cult of Isis at Rome: There were two major temples to Isis and Serapis by the end of the Republic. The main temple was on the Campus Martius, and known as Isis Campensis, and a smaller temple stood at the foot of the Oppian (on what is now the Via Labicana). The third Augustan Region of Rome took its name from the Oppian temple: Regio III was “Isis et Serapis”.
The emperor Hadrian (reign 117-168 AD) was particularly interested in the cult of Isis and Serapis, and built a Serapeum at his villa at Tivoli.
Yet the Romans had a love-hate relationship with Isis. Her temples were repeatedly weeded out of the area within city walls; from time to time the cult was banned.   ← Back

Destruction of the Iseum: The emperor Theodosius I (reign 379-395 AD), a Christian, forbade all pagan cults (and also some Christian cults as well, such as Arianism). The cult of Isis and Serapis was particularly targeted after the violent reaction of followers of Isis and Serapis in Alexandria in 391, when Christians were killed and the Serapeum of Alexandria, one of the wonders of the world, was destroyed. Thus, some archaeologists believe the fire that consumed the Iseum of the Campus Martius could have equally been a deliberate demolition in response to the events at Alexandria, mainly because it seems the temple priests were forewarned: they hid many of the temple’s treasures in a small room. These were found, unharmed, during excavations in the Via del Beato Angelico in 1833.
In the late 1500s, diggers found columns of giallo antico marble, still upright, under the church. But the columns were so damaged by fire that they crumbled at the touch.   ← Back

San Macuto or Mahutaeus or Malo: In spite of his vaguely Egyptian-sounding name (Mahutaeus in Latin, Macuto or Macuteo in Italian, Maclou or Malo in French) Macuto came from Wales. He was the first bishop of Aleth, a city on the coast of Brittany, and died in around 620. He is considered one of the founding saints of Brittany, and in the 12th century the entire area of Aleth became known as Saint-Malo.   ← Back

The caduceus: The winged staff with its double serpents is a very antique symbol, originating in Mesopotamia perhaps as early as 4000 BC. In Egypt it became the symbol of Hermanubis, the messenger god with the jackal head that assimilates the Greek Hermes and Egyptian Anubis.
The caduceus is often confused with the rod of Asclepius and used as a symbol for the health professions, an error stemming from 1902 when it became the symbol of the U.S. Army Medical Corps, who apparently did not know the difference.   ← Back

The Obelisk of Macuteo: This obelisk was taken from Heliopolis, and bears the name of Ramesses (or Ramses) II (reign 1279-1213 BC, third pharaoh of the 19th Dynasty).
Although no record was kept, it was probably found around 1600 when the apse of Santa Maria Sopra Minerva was being expanded. It was then set up in front of the Church of San Macuto, not too far away.   ← Back

The Pulcino: The little elephant serving as a base for the obelisk was designed by Bernini for pope Alexander VII Chigi, and was meant as an allegory for the idea that a strong body is needed to support a strong mind. It was sculpted by one of Bernini’s students, Ercole Ferrata, in 1667.
The word “pulcino” probably comes from a “correct spelling” of the 17th-century Roman name for the statue, porcino, “little pig” (Roman dialect tends to swap l and r).   ← Back

The Obelisk of the Minerva or Minervaeus: The obelisk was found in the garden of the Dominican fathers of Santa Maria in 1665, at about 3.5 metres (12 ft.) underground, and set up in front of the church in 1667.
From the hieroglyphic text, scholars have deduced that the obelisk honours the pharaoh Apries (reign 589-570 BC), fourth pharaoh of the 26th Dynasty, simply because his name was scratched out during revolts sometime before 570 BC. From the inscription we also know that this obelisk once stood in the temple of Osiris at Sais, an ancient town of the western branch of the Nile Delta.   ← Back

Madama Lucrezia: Exactly where and when it was found is not known. It was placed at the corner of the Basilica of Saint Mark on Piazza Venezia in 1465, and is known as one of the Talking Statues of Rome. The statue got its name from one of its owners, Lucrezia d’Alagno (1430-1475), a Neapolitan noblewoman who lived in the area at the end of her life.

Below: Isis (or perhaps a priestess of Isis), now at the Piazza di San Marco (southwest corner of Piazza Venezia)

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Minerva Chalcidica: It was a round temple with four stairways, built by the emperor Domitian (reign 81-96 AD) and perhaps called “Chalcidica” because it stood at the entrance to Domitian’s Divorum, of which it was a part (a chalcidicum is a covered colonnade serving as a monumental entrance).
The Divorum and temple of Minerva were a portion of the extensive rebuilding Domitian undertook in the Campus Martius after the disastrous fire in 80 AD.
← Back to Santo Stefano del Cacco
← Back to the Church of Santa Marta

The Divorum: This was a large, rectangular porticus built by the emperor Domitian in honour of his deified father Vespasian and brother Titus, in the area of the Campus Martius destroyed by the fire of 80. It seems to have been a sort of garden containing temples to the two emperors. Its southern wall was found under the Via del Plebiscito in 1925.   ← Back

The Temple of the Divine Hadrian: We know from the “Life of Antoninus Pius” and the “Life of Lucius Verus” in the Historia Augusta that the temple was dedicated by Antoninus Pius in 145 AD.
Antoninus Pius did a great deal to help along the memory of Hadrian, who some apparently considered far from divine, notably because of that sentimental business of Antinous. The Senate dragged their feet when Antoninus Pius proposed they deify him, but in the end it went through. Antoninus Pius also reversed the death-sentences Hadrian had proclaimed (saying Hadrian meant to do it himself), completed Hadrian’s Mausoleum, and rigorously respected Hadrian’s wishes in naming Lucius Verus and Marcus Aurelius as his own successors.
Three centuries after its construction, the temple was in ruins and its identity forgotten. By the 1500s it was being used as a “brefotrofio”, a home for abandoned children (from the Greek brefos, “newborn”). Pope Innocent XII Pignatelli transformed it into his customs house in 1695. It was confusedly called the “Basilica of Neptune” until 1904 when a German high-school teacher and classical philologist, Hans Lucas, identified it as the Temple of the Divine Hadrian.
Archaeologists think the temple originally had 15 columns on the long sides and eight across, and formed a pair with the earlier Temple of Matidia just to the west.
Both temples were surrounded by a walled temple precinct with (probably) two monumental entrances. One, known as the Arch of the Antonines or the Parthian Arch of (Lucius) Verus or the Arco de’ Pazzarelli, was destroyed sometime before 1527. It was decorated with the relief of Hadrian’s arrival in the city (the adventus), today in the Capitoline Museums. Other remains of the arch were found in 1942 under number 333 of the Via del Corso.   ← Back

The Collegio Romano: This large building, which occupies the entire north side of the Piazza del Collegio Romano, was, and still is, a school, although no longer administered by the Jesuits. It was instituted by their founder Ignatius of Loyola in 1551. The school was first housed in the Via del Gesù before the Palazzo del Collegio Romano was completed in 1582.   ← Back

The Church of Santa Maria Sopra Minerva: It is a Dominican church, built in the 13th century atop the ruins of an 8th-century church known as the Virgin Mary of the Minervum. That older church re-used the walls of the Voting-Pens, which had been confused with the Iseum nearby, when Isis had been mostly forgotten and vaguely remembered as Minerva. In 1600, the apse was enlarged, this time really over the old temple precinct of the Iseum, and numerous artefacts from the cult of Isis and Serapis were found.
Santa Maria Sopra Minerva is rich in important artworks by Pirro Ligorio, Michelangelo Buonarroti, Filippino Lippi, Giacomo della Porta, Carlo Maderno, Melozzo da Forlì, Gian Lorenzo Bernini, Mino da Fiesole... the list is long. Saint Catherine of Siena and Fra Angelico are buried within.
It was in the chapterhouse (sala capitolare) of Santa Maria Sopra Minerva that one of the darkest episodes of the history of science occurred: on 22 June 1633 Galileo renounced his own work, and was condemned to a prison term at the discretion of the Sant’Uffizio or Roman Inquisition (which turned out to be a few weeks of house arrest at Villa Medici in Rome, then five months of confinement in Siena).   ← Back

The Pumpkinification of Claudius: The satire was anonymous (of course), but Cassius Dio dropped Seneca the Younger’s name as its author. The point of the satire was that if the Senate continued to deify arrogant and inarticulate emperors like Claudius, people would stop believing in the gods.
Yet... the gods weren’t sacred. 400 years before the date of the Pumpkinification, we read in the Bacchides of Plautus:

Lydus: What gods dwell there?
Pistoclerus: Venus, Cupid.... Good Kisser.
Lydus: What god is this “Good Kisser”?
Pistoclerus: [...] So old, and he still doesn’t know the names of the gods.

Or Jupiter, disguised as Amphitryon in order to take advantage of Amphitryon’s wife, or Mercury disguised as Sosia beating the real Sosia who cannot understand why he is beating himself up. And these plays were presented at religious festivals...   ← Back

The deification of emperors: The idea of making one’s self into a god perhaps came to Rome from contact with Egypt, where the god-king was well established. Romulus was supposed to have ascended to heaven on a cloud, but we first hear about this in the imperial age (Plutarch, writing about 75 AD). The first imperator to be divinised was Julius Caesar, helped along by his claim that he descended from the goddess Venus, and by the comet which appeared four months after his death, in the month of Quinctilis (later renamed Julius, July). For the Romans, who honoured the spirits of their ancestors in any case, a cult honouring Caesar was not too shocking.
The Roman people seem to have held a few of their rulers in such esteem that godhood seemed appropriate: Julius Caesar and his heir Octavian, Trajan, and the saintly Antoninus Pius.
One became a god by decree of the Senate, a bit like papal canonisation.   ← Back

The Cella of the Temple of Hadrian: The huge vault, in concrete mixed with lighter and lighter materials as it rises, is still visible. Alas the Chamber of Commerce, which now occupies the building, does not offer any chance to view it (2013) except in the case of occasional conferences and concerts which are held there, such as “Museum Night” (La Notte dei Musei, usually held in May).   ← Back

Vicolo della Spada di Orlando: The legend says that Roland, the leading knight of Charlemagne, tried to destroy his mythical sword Durendal by striking it against a stone after being defeated at the Battle of Roncesvalles, so that Durendal would not fall into enemy hands. Roncesvalles is actually in northern Spain, but in the Middle Ages, Romans were not so good in geography, so they had no problem in believing that the battle took place in Rome.   ← Back

Antinous: The emperor Hadrian’s favourite who drowned in the Nile in 130 AD. In the “Life of Hadrian” of the Historia Augusta we read that “for this youth he wept like a woman”. Hadrian deified the young man, unprecedented for someone not of the imperial family, and created a cult to him which became popular in the eastern Greek-speaking part of the empire.   ← Back

The Arco de’ Pazzarelli: Or “Arch of the Little Lunatics” named for the asylum called “L’Ospedale di Santa Maria della Pietà dei Poveri Pazzerelli” which stood just to the east of Piazza di Pietra from 1569 to 1725.   ← Back

The Temple of the Divine Matidia: From the Marble Plan, we know that it stood just north of the Saepta, with its long sides on the north and south, and was very likely quite similar to Hadrian’s temple, with eight columns on the short sides and thirteen or fifteen columns on the long sides. Seven of these columns were found in the Vicolo della Spada di Orlando and surrounding houses.
The temple was built around 120 AD, and flanked by two porticoes called the Basilicas of Marciana and Matidia (mother and daughter, niece and great-niece of the emperor Trajan). We have an idea of what it looked like from a medallion of Hadrian’s.

Below: Bronze medallion of Hadrian. The barely-legible inscription beneath the temple reads DIVAE MATIDIAE SOCRUI (“To the Divine Matidia, Mother-in-Law”)

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Mothers-in-law: If many things have changed since the high empire, it would appear mothers-in-law have not. Terence’s play Hecyra (“The Mother-in-Law”) was a legendary flop: every time he tried to stage it, people walked out, gladiators trashed the theatre, etc. To be fair, the play did reach the end on the third staging, and has also survived from antiquity.
The character of the mother-in-law in the play is much as we would expect: a suffocating, self-sacrificing matron.
Hadrian’s mother-in-law Matidia was quite a different story: her mother, Ulpia Marciana (~48-114 AD), was the emperor Trajan’s sister, and Trajan, who was childless, treated Marciana’s daughter Matidia as his own, and Matidia’s daughter Vibia Sabina (Hadrian’s wife) as his own grandchild. Thus by deifying Matidia, Hadrian reinforced his own claims to being a member of the divine imperial family.   ← Back

Trajan (Marcus Ulpius Traianus): He reigned from 98 to 117 AD, at a time of great expansion and prosperity for the Roman empire. He left a legacy of wise, benevolent administration and brilliant architectural achievements, such as his Column, Forum, and markets (along today’s Via dei Fori Imperiali).
He was so revered by the Senate and the Roman people that he was deified at his death. His funerary urn was placed in the pedestal of the Columna Cochlis, the spiral column commemoration his Dacian victories at the centre of his forum.   ← Back

The Obelisk of Psammetichus II: It was one of two obelisks that Octavian brought from Egypt in 10 BC, to mark the conquest of Egypt and its entry into the empire as a Roman province. One, the Obelisk of Ramses II, was set up in the Circus Maximus. The other, the Obelisk of Psammetichus II, became the gnomon of the Horologium Augusti and one of the symbols of the Campus Martius.
The obelisk was erected by the pharaoh Psammetichus II (also written Psamtik II and Psammetikos II), who reigned in Egypt 595-589 BC. The hieroglyphs are in very bad shape, but the names of the king as ruler of Upper and Lower Egypt and master of Iunu, along with other titles, are still legible.
The inscription on the base reads:

Imp Caesar divi fil
Augustus
pontifex maximus
imp XII cos XI trib pot XIV
Aegypto in potestatem
populi romani redacta
soli donum dedit
The emperor, son of the Divine Caesar, Augustus,
Pontifex Maximus, holding imperium for the 12th time,
consul for the 11th time, holding the tribunician power for the 14th time,
having brought Egypt into the power of the Roman people,
made this offering to the sun.

The date would have been 10 BC, twenty years after the deaths of Mark Antony and Cleopatra and the incorporation of Egypt into the empire.   ← Back

Pliny’s Natural History, book 36, chapter 15: “The one [obelisk] that has been erected in the Campus Martius has been applied to a singular purpose by the late Emperor Augustus, that of marking the shadows projected by the sun, and so measuring the length of the days and nights. With this object, a stone pavement was laid, the extreme length of which corresponded exactly with the length of the shadow thrown by the obelisk at the sixth hour [noon] on the day of the winter solstice.
After this period, the shadow would go on, day by day, gradually decreasing, and then again would as gradually increase, correspondingly with certain lines of brass that were inserted in the stone; a device well deserving to be known, and due to the ingenuity of Facundus Novus, the mathematician.
Upon the apex of the obelisk he placed a gilded ball in order that the shadow of the summit might be condensed and agglomerated, and so prevent the shadow of the apex itself from running to a fine point of enormous extent, the plan being first suggested to him, it is said, by the shadow that is projected by the human head.
For nearly the last thirty years, however, the observations derived from this dial have been found not to agree: whether it is that the sun itself has changed its course in consequence of some derangement of the heavenly system, or whether that the whole earth has been in some degree displaced from its centre, a thing that, I have heard say, has been remarked in other places as well; or whether that some earthquake, confined to this city only, has wrenched the dial from its original position; or whether it is that in consequence of the inundations of the Tiber, the foundations of the mass have subsided, in spite of the general assertion that they are sunk as deep into the earth as the obelisk erected upon them is high.”
–Pliny the Elder, Natural History, ~70 AD. Translated by John Bostock and T. H. Riley.
← Back to the Campus Martius
← Back to the Baths of Diocletian

The Horologium Augusti as a clock: Even though only the meridian has been found, archaeologists are unable to say if the sundial was used as a clock or just as a meridian when it was first set up in 10 AD. The clues would have been erased by the time of emperor Claudius (reign 41-54 AD), who expanded the pomerium, with the new pomerium line running just 20-30 metres west of the clock’s meridian line, thus cutting off the morning readings of the sundial, if they ever existed. The whole stone pavement containing the hypothetical hour lines may have already been buried or been useless as a clock by 40 AD, which may be why the emperor Claudius did not hesitate to place the pomerium there, retaining only the meridian. But it is unlikely that the Horologium Augusti was ever anything more than a meridian.   ← Back

The Etesian Winds: These are the prevailing winds in the summertime in the Aegean Sea between Greece and Turkey, blowing from the north to the south in the afternoon, and felt in all of Greece.
Similar winds blow landward from the Ionian Sea and the Tyrrhenian Sea in summertime. The Tyrrhenian wind is the famous “ponentino” which blows in from the west, cooling Rome is the summer months. (One wonders why the Ponentino was not mentioned on Octavian’s meridian, rather than the Etesian wind, but that is yet another mystery. Perhaps “the Etesian ceases” was just a conventional way of saying “summer ends”.)   ← Back

Site of the Meridian Line of the Horologium Augusti: The meridian lies 1.5 metres (5 ft.) above the foundations laid in 10 BC, and shows signs of having been raised and recalibrated over the years, since it is set in a travertine pavement dating from about a century later. It lies 7 metres (23 ft.) below street level, and is under about 10 cm (4 in) of water. In fact the pavement and the meridian line lay under a pool or a basin which was built over them in about 140-200 AD, and were preserved because they were covered with waterproof concrete.
The site has been closed for visits, even private, since 2012.   ← Back

Piazza San Lorenzo in Lucina: The square lies in the centre of the area where Octavian erected the sundial and the Altar of Peace. Underneath the church are two insulae built in the 2nd century which prove that by then, the city had crowded into the area between the Ara Pacis and the Horologium augusti.   ← Back

The Column of Antoninus Pius: This honorary column to a most beloved emperor was found in 1703 between the Palazzo di Montecitorio and the Via di Campo Marzio. In 1705, pope Clement XI Albani planned to have it set up but the project was never carried out and the shaft and base were left in a shed at the Piazza di Montecitorio. The base was set up at Montecitorio much later, in 1741. By 1759, plans to raise the shaft had been abandoned and a fire damaged it beyond repair where it lay behind Palazzo Montecitorio. In 1787 the base was moved to the Vatican where it can be seen today.
The column had been erected (of course) by the men emperor Antoninus Pius had adopted and named his heirs: Marcus Aurelius and Lucius Verus.
The base is an invaluable document about the imperial cult. Besides the apotheosis (divinisation) of Antoninus Pius and Faustina, riding to heaven on the back of a Winged Genius, it shows us the personification of the Campus Martius, holding the great sundial of Augustus, and on the short sides, scenes of the decursius, the gallop of the cavalry around the funeral pyre.

Below: The base of the Column of Antoninus Pius, showing the personification of the Campus Martius holding the Horologium at left, and the goddess Rome leaning on her shield at right. 161 AD. Now in the Vatican Museums, Courtyard of the Pinacoteca Vaticana. Photograph © Lalupa, 2006.

Along with the column, a curious altar was discovered in 1703, exactly 100 Roman feet (29.6 metres or 97.11 ft.) to the southeast. The altar was square and surrounded by a wall and by columns. Archaeologists have concluded it was built to mark the spot where the funeral pyre (ustrinum) of the emperor had burned. Two more such altars were found under Palazzo Montecitorio during work in 1906.
← Back to the Campus Martius
← Back to Francesco Bianchini, Baths of Diocletian

Decursius: Or decursio equitum. Literally, the “equestrian parade”, it was a ritual associated with the death of a general or the divinisation of an emperor: the cavalry galloped counter-clockwise around the funeral pyre.

Below: The decursius of Antoninus Pius. Base of the column of Antoninus Pius, 161 AD. Vatican Museums. Photograph © Sailko, 2010.

← Back to the Campus Martius, column of Antoninus Pius
← Back to the Tombs of Two Emperors

The Five Good Emperors: A term coined by historian Edward Gibbon (Decline and Fall of the Roman Empire, 1776). These are:

- Nerva (reign 96-98 AD)

- Trajan (reign 98-117 AD)

- Hadrian (reign 117-138 AD)

- Antoninus Pius (reign 138-161 AD)

- Marcus Aurelius (reign 161-180 AD)

The period 96-180 corresponds to the Golden Age of the Roman empire, when it was at its maximum extent. Transitions of imperial power were peaceful, each man naming his successor. Marcus Aurelius, the only man who had a son, Commodus, most unfortunately had to break with this practice.   ← Back

The Temple of the Divinised Marcus Aurelius and Faustina the Younger: Even though almost no remains have been found (just a bit of coffered ceiling in 1960), we have a good idea of where it stood, since the actual house of Adrastus, caretaker of the column, was found in 1777, along with the inscription in which we read that his house was to be built “behind the column and the temple of Marcus and Faustina”. This puts the temple at the south-eastern edge of Piazza di Montecitorio, just west of the column which faced the Via Lata (today’s Via del Corso) on the east.

Below: The petition Adrastus inscribed on the wall of his house, found in place in 1777 at the southeast corner of Piazza di Montecitorio. Cast of the original in the Vatican Museums. Museum of Roman Civilisation (Museo della Civiltà Romana), Rome.

The inscriptions found at the house of Adrastus the custodian provide valuable information not just about public institutions but also about where the temple stood.
On the door jamb of his little house, Adrastus inscribed both his own petition and the accompanying documents of the rationalium (administrators) who not only authorised him to build his house on public land in order to take care of the “hundred-footer” (the column, 100 Roman feet tall) but also allotted him building materials. In addition, they specified that the house was to be his personal property, and that his children could inherit it (which was the whole reason for inscribing this long text for posterity). Since the letters are dated, we know that the column was completed at least by 192 AD.
To be honest, as you can see, the petition of Adrastus is missing the right half, so we don’t know whether he wrote just “behind the column” or “behind the column and the temple”. It is the mention of Faustina’s name which leads us to believe he built behind the temple, dedicated to the deified couple, whereas the column bore the name of Marcus Aurelius only.   ← Back

The Statue of Venus in the Pantheon: We have this account of the marvellous statue of Venus in the Pantheon from Pliny the Elder, writing around 77 AD. The story is actually about the bet that Cleopatra made with Mark Antony, who “stuffed himself daily with rare foods”. She could serve a meal so extraordinary, she wagered, that it would be worth 10 million sesterces. Mark Antony took her on. The next day she set before Mark Antony a perfectly ordinary meal, at which he laughed, declaring himself winner of the bet. Cleopatra told him to wait for dessert, which was a glass of vinegar for each. She was wearing at the time pearl ear-rings, the “two largest pearls of all history, bequeathed to her by kings”. She took off one pearl, dropped it into the vinegar where it dissolved, and drank it. As she was about to serve the second pearl to Mark Antony, Lucius Plancus, who was refereeing the bet, stopped her and declared Cleopatra the winner.
When Cleopatra was captured by Octavian, the last giant pearl fell into Roman hands. It was cut in two and mounted as the ear-rings of Venus in Agrippa’s Pantheon.
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Palazzo Wedekind: It was built in 1814 over the 1659 Palazzo Ludovisi, which was built over medieval houses which were built over the ruins of the ~180 AD Temple of the Divine Marcus Aurelius and Faustina the Younger. The 1814 building, which we see today, was constructed for the Postal Service of the Papal States, appropriately with a front portico of Ionic columns taken from a Roman villa found in the ruins of Veii.
It takes its name from its owner in 1852, the wealthy patron of the arts Karl Wedekind.   ← Back

Meditations of Marcus Aurelius Antoninus: The emperor Marcus Aurelius wrote this series of “Thoughts to Myself” (as he called them) during the years he was on campaign against Germanic tribes to the north and the east of the empire, from 171-180 AD.
He wrote in Greek, which was the language of the Stoic philosophy permeating his life. These short reflexions, as his own title suggests, were probably never meant to be published. Just two manuscripts of the Meditations survived antiquity: one, now lost, was copied in 1558, the other is in the Vatican.   ← Back

The wars of the Column of Marcus Aurelius: The column tells the story of the expeditions made by Marcus Aurelius against Germanic tribes (the Marcomanni and the Quadi) and also perhaps the “Sarmatian” expedition against the Iranian-speaking Iazyges. These took place in 172-175 (against the Marcomanni and the Iazyges) and 177-180 (against the Marcomanni and the Quadi). In 176, Marcus Aurelius celebrated a triumph at Rome for his German and Sarmatian victories.
We have very little alas in the way of a written history for these wars, so historians struggle to identify the scenes on the column. One, the “Rain Miracle”, certainly took place in 172 AD; another, crossing the Danube, can be dated from a coin of 172 AD showing the same scene. There is a scene of Commodus assuming the toga virilis which they can also securely date to 175 AD. This scene is placed just before the winged Victory writing on a shield that separates the two expeditions.
It was during these wars that Marcus Aurelius wrote his Meditations. In book 1, chapter 15, he noted that he was “among the Quadi at the Granua” (the Granus or Hron is a river in modern-day Slovakia, affluent of the Danube).   ← Back

Commodus: Lucius Aurelius Commodus was the only son of emperor Marcus Aurelius who survived childhood. He was named heir at age five along with his four-year-old brother Marcus Annius Verus (who died at the age of seven).
Cassius Dio, who was a member of the Senate during the reign of Commodus, provides a horrific account of the years between 182-192 as Commodus succumbed to megalomania, leaving the administration of the empire in the hands of corrupt men.
In 192, Commodus was assassinated, making way for the disorders that strongman Septimius Severus put an end to.   ← Back

The Antonine Plague: Also known as the “Plague of Galen” since it was described by Galen who was called to Aquileia in 168 AD to take care of Roman soldiers suffering from the disease. It first broke out during the Parthian war, among the army fighting on the west bank of the Tigris, in 165 AD. It was rapidly spread by Roman troop movements, to Italy, Gaul, and along the Rhine and the Danube.
There is still some discussion as to the exact nature of this “pestilence”, but a 1973 study convincingly identified it as smallpox. The fatality rate of the disease in the 2nd century is unknown – we only have a phrase from Cassius Dio’s Roman History, Book 73: “In a single day, two thousand persons often died in Rome”. The emperor Marcus Aurelius recalled it with anguish on his deathbed:

Quid de me fletis et non magis de pestilentia et communi morte cogitatis?
“Why do you weep for me, when the plague and death awaiting all should more occupy your thoughts?”
– Historia Augusta, “Marcus Aurelius”, 28.4.

Some historians consider the smallpox epidemic the “beginning of the end”, given the troubles that followed, and maintain that the Roman empire never recovered from the hemorrhage of population it caused — although Cassius Dio declares the pestilence was nothing compared to Commodus.   ← Back

Gothic Migrations: Toward the end of the 2nd century, Gothic populations had grown in number and they moved into the area around the Black Sea, displacing other Germanic peoples who were pushed south and west toward the Romans.
One of those displaced tribes, the “Marcomanni” (Markomannen, “Men of the Border”), allied themselves with other Germanic tribes to invade Roman territory.   ← Back

Trajan’s Column: It was the idea of Apollodorus of Damascus, an architectural genius, and was made in commemoration of Trajan’s Dacian wars (fought in 101-102 AD and in 105-106 AD).

Below: Trajan’s Column, behind the ruins of the basilica of Trajan (Basilica Ulpiana, from “Ulpius”, Trajan’s family name).

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The Church of Santa Marta al Collegio Romano: The complex started in 1543 as a Jesuit home for “women living in sin”. Today, the deconsecrated church and monastery are the property of the Italian state: the monastery serves as a police station for the 1st circumscription, and the church is occasionally used for conferences.   ← Back

Ballomar or Ballomarius: Leader of the Germanic allies who attacked and defeated the Romans at Carnuntum (near Vienna), thus starting the Marcomannic wars (~167-172 AD). He reached far south into what is now the Veneto region. Ballomarius was mentioned by Cassius Dio in the “Roman History”, Book 72, as negotiating for peace in 167 AD. Seeing his chance when the legions were engaged in Dacia, he quickly turned against Rome. Despite early successes, he was forced to surrender in about 172 AD.   ← Back

The Base of the Column of Marcus Aurelius: Pope Sixtus V had the original reliefs of winged victories and barbarians on the base chipped off in order to reinscribe it. Fortunately they were drawn prior to their disappearance by 14th-century artists.   ← Back

Statue of the god Thot as a baboon: The statue is today in the Gregorian Egyptian Museum of the Vatican. The base is inscribed in Latin and Greek, bearing the names of two 1st-century Greek sculptors, Phidias and Ammonios (in Greek), and the words “Seal affixed by Caelius Priscillianus Maximus (curator), Quintillus and Priscus consuls” (in Latin), which dates it to 159 AD.
For more information on the statue, see: mv.vatican.va: Statua di Thot cinocefalo.   ← Back

The skeleton of the Basilica of Neptune: Near the skeleton a clay pot was found, filled with coins dating from the 1200s, which allowed archaeologists to conclude that the roof collapsed sometime toward the end of the 13th century.   ← Back

The Calendars of the Romans: During the Republic, the Roman calendar was a huge mess. The calendar left by King Numa Pompilius was a lunar calendar, and thus did not match the solar year, being too short by about 11 days. It was up to the pontifex to adjust the calendar by adding extra days, which he did about once every two years, adding 22 days after February. This was called the “intercalary month”. But this was not always done: when Julius Caesar was pontifex, for example, he could not deal with the calendar because he was away fighting in Gaul. Or an intercalation could be blocked by the Senate, for example to prevent Caesar from taking charge of his provinces (since the Senate would not meet). In any case, the calendar was a victim of political agendas and by 46 BC it was (again) way off, about three months short, so that harvest festivals were being celebrated in spring.
Practical Julius Caesar put an end to the mess, and in 46 BC, with the help of the Alexandrian astronomer Sosigenes and his own experience of Egypt (where the calendar was solar, not lunar), he made the necessary adjustments and set down hard-and-fast rules so that nobody could fiddle with it again.
Simple as it was, the pontifices still couldn’t do it right, since they counted inclusively, adding an extra day every third year, and by 8 BC the calendar was off once more. Octavian fixed the calendar by declaring a moratorium on leap years until 8 AD, explained to them how to count leap years properly, and set up his famous Horologium in the Campus Martius so that there would be no further questions. That was the Julian calendar and it is still the basis for the calendar we use today.
Caesar’s simple method meant that the year was a few minutes longer than the actual solar year (he may have thought that more complicated rules would have been too much for the pontifices – he was evidently right), and would gain a full day over the solar year every 128 years. By 1582, the calendar had gained ten additional days: by then 21 March fell ten days after the actual spring equinox, an event that is easily observed if you happen to be watching, since the sun is straight overhead at noon and the length of day and night are equal. Pope Gregory XIII Boncompagni (he of the granaries) fixed the error in 1582, simply by chopping ten days out of October, and refining the rules for leap years (years divisible by 100 will not have a leap year unless they are also divisible by 400). The repaired calendar was named “Gregorian” after Pope Gregory and is used by just about everyone on the planet today. (Even though it is not perfect either, it will gain a day by the year 3200.)   ← Back

Ides, Nones, and Kalends (Roman Lunar Calendar): The Romans had the curious habit of counting days backwards, that is of numbering days before some given date. This was a side effect of using a lunar calendar, when the appearance of the new moon would give them the number of days until the full moon. The appearance of the new moon was the kalends, that is 13 or 15 days before the full moon. The half-moon was nones, eight days before the full moon, and the full moon was ides. The lunar calendar was abandoned as far back as King Numa, but the words Ides, Nones, and Kalends persisted, along with the habit of counting backwards from a given day.
Thus, for 29 October, you would have to say “4th day of the Kalends of November” (four days previous to 1st November).
The Greek calendar had no such method of numerating backwards, so for the Romans, to say “At the Greek Kalends” was another way of saying “never”.
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