Rome: The Pantheon

The Pantheon.

The Pantheon is one of Rome’s most famous landmarks. In its current form, it dates from the second century. What is special, is that it is still more or less in one piece and that it has never been substantially modified. Rome does have a few other buildings from the Roman era that are also still intact, for instance the Republican era temples on the Forum Boarium (see Rome: Santa Maria in Cosmedin), which are at least two hundred years older. However, none of these are as impressive as the Pantheon. Since it is officially a church, and has been a church for over 1.400 years, its formal name is the Santa Maria ad Martyres, but everybody calls it the Pantheon and the building is advertised as such both in travel guides and on street signs.

The Pantheon is most famous for its gigantic concrete dome, a true marvel of Roman engineering. Since it is hardly visible from street level, it is best to go to a high lookout point to admire it from a distance. The Piazzale Giuseppe Garibaldi on the Gianicolo offers a panoramic view of the entire city. Even better is the lantern of the dome of Saint Peter’s Basilica. It should be noted that the dome of the Pantheon is in fact wider than that of Saint Peter’s, designed by the famous Michelangelo: it has a diameter of 43.30 metres vs. 41.47 metres for Michelangelo’s dome (Brunelleschi’s dome in Florence is about 70 centimetres wider than that of the Pantheon).

Dome of the Pantheon, seen from the ‘cupola’ of Saint Peter’s Basilica.

Early history

The first version of the Pantheon was built by Marcus Vipsanius Agrippa in 27 BCE. His name is mentioned on the frieze of the portico or pronaos of the temple:

(“Marcus Agrippa, son of Lucius, consul for the third time, built this”)

Remains of the Temple of Neptunus. Note the maritime motifs: scallops, tridents and dolphins.

The Pantheon was about half a mile south of the Mausoleum of Augustus. This part of Rome was known as the Campus Martius in Antiquity. It was not a residential area, but rather a somewhat soggy open space outside the walls of the city where the Roman legions exercised and meetings of the popular assembly were held. To the east of the Pantheon were the Saepta Julia, the voting area also completed by Agrippa, and the double temple of Isis and Serapis (see Rome: Santa Maria sopra Minerva). To the south and touching was a large hall known as the Basilica of Neptunus, and to the south of the basilica were the Baths of Agrippa. To the west of these Baths was a large artificial reservoir known as the Stagnum Agrippae, which was part of an ingenious system of water management. A canal known as the Euripus drained the watery areas of the Campus Martius. The Roman historian Suetonius was not exaggerating when he wrote that “many magnificent structures were built by Agrippa in particular”.[1]

The name Pantheon is often translated as “temple of all the gods”. However, a better translation is probably “completely divine”, just like the word “panagia” – one of the titles of the Virgin Mary – means “all holy” and not “all saints”, and the word “panormos” means “complete port”. There is no evidence that the Pantheon was indeed a temple for all the Roman gods, and the best guess is probably that it was “dedicated to the cult of the princeps [i.e. Augustus] and his divine ancestors”.[2] The name seems to have puzzled later generations. The historian Cassius Dio, writing over two hundred years after the completion of Agrippa’s Pantheon wrote that:

“it has this name, perhaps because it received among the images which decorated it the statues of many gods, including Mars and Venus; but my own opinion of the name is that, because of its vaulted roof, it resembles the heavens.”[3]

Interior of the Pantheon. You will not be the only visitor…

The shape of Agrippa’s building has been hotly debated in the past. However, I concur with the opinion expressed by the authors of The Atlas of Ancient Rome, edited by Andrea Carandini, one of the foremost experts on the geography of Ancient Rome. They conclude that “Agrippa’s Pantheon must also have been circular with the same dimensions and orientalisation, not rectangular as previously believed”.[4] According to the aforementioned Cassius Dio, there were statues of Augustus and Agrippa in the niches of the pronaos and statues of the Divine Gaius Julius Caesar, Mars and Venus inside the temple. Caesar was Augustus’ adoptive father, who claimed to be descended from Venus and who commissioned a temple for Venus Genetrix on his own forum. Augustus would later build a temple for Mars Ultor on his forum. There indeed seems to be a strong case that the Pantheon was closely associated with the cult of the emperor and the Julio-Claudian dynasty.

Carandini furthermore hypothesises that the triangular pediment of the pronaos may have originally featured a relief showing Mars, Rhea Silvia, shepherds and the wolf nursing Romulus and Remus. The Romans believed that this was the spot where their legendary first king Romulus had mysteriously ascended to Heaven.[5] Later writers sought to connect Romulus’ apotheosis to that of Augustus, the first true Roman emperor. Suetonius, writing about Augustus’ imminent deification, claims that:

“As he was bringing the lustrum to an end in the Campus Martius before a great throng of people, an eagle flew several times about him and then going across to the temple hard by, perched above the first letter of Agrippa’s name.”[6]

This temple may have been the Pantheon, and the first letter of Agrippa’s name is of course the ‘M’, for ‘mors’ or ‘death’. The event is said to have taken place in the year 14 CE, shortly before Augustus’ death.

Tomb of Victor Emmanuel II, first king of a unified Italy.

The Pantheon we see today is a second century reconstruction. This area of Rome – the ninth region, known as Circus Flaminius[7] – was almost entirely destroyed in the great fire of 80 CE. Based on a casual remark in the fourth century Historia Augusta[8], it used to be thought that the temple was restored by the emperor Hadrianus (117-138). However, it is now unanimously accepted that Hadrianus completely rebuilt the Pantheon, perhaps continuing a project started by his predecessor Trajanus (98-117). Archaeological evidence – brick stamps to be exact – rules out the conclusion that the Pantheon was merely restored. The Basilica of Neptunus was also preserved and part of it seems to have been used as a library. The Pantheon itself seems to have been converted into an imperial audience hall, so it presumably lost its function as primarily a religious building, if ever it had such a function in the first place. The tympanum now featured an eagle inside a wreath clutching a ribbon with its talons, possibly a reference to Augustus’ eagle mentioned above. For some reason, Hadrianus decided not to leave his own name on the new monument, instead copying the original inscription mentioning Agrippa.

The Pantheon as a church

The Pantheon was restored in 202 by the emperor Septimius Severus (193-211) and his son, the future emperor Caracalla (211-217), while the Christian historian Sextus Julius Africanus is said to have organised a bibliotheca Panthei for the emperor Severus Alexander (222-235).[9] In 391 or 392, the emperor Theodosius I (379-395) suppressed all the non-Christian cults in the Roman Empire, closing the temples of the traditional gods and ending the use of the Pantheon as a religious building. The building probably continued to be used as an audience or assembly hall, but the statues of the pagan gods were certainly removed. In late 608 or early 609, the Eastern Roman emperor Phokas (602-610) donated the Pantheon to the Church. Pope Bonifatius IV (608-615) subsequently consecrated the building as a Christian church and dedicated it to the Virgin Mary and all the martyrs. The Pantheon now acquired its official name Santa Maria ad Martyres.

Oculus of the Pantheon.

Soon, all sorts of silly myths sprung up with regard to large hole in the dome, the so-called oculus. In one version of events, Pope Bonifatius made the sign of the cross to bless the dome, and lo and behold, suddenly the big hole appeared. An even sillier tradition claims that as soon as the Pope had consecrated the Pantheon, hordes of demons tried to flee the building. A particularly large one was said to have made the oculus with his gigantic horns, trying to force his way out. Of course this is all nonsense. The oculus – which has a diameter of close to nine metres – was made for one purpose only: light. The Pantheon has no windows and the only other source of light are the front doors. And yes, this means that rainwater and snowflakes can enter the Pantheon through the oculus. This is quite a spectacular sight; see for instance this movie. A drain and the slightly sloping floor make sure that things do not get all wet and messy inside.

Although the Pantheon has not been structurally altered, it had been stripped off many of its treasures. As has already been discussed, there was obviously no place for pagan statues in a Christian church. The Eastern Roman emperor Constans II (641-668) was accused of having stolen the gilded bronze roof tiles during his visit to Rome in 663 and some of the original columns from the left side of the pronaos were also removed and disappeared at an unknown date during the Middle Ages. If the cassettes of the coffering once had bronze stars attached to them, as has been assumed, these are also no longer there. During the pontificate of Pope Urbanus VIII (1623-1644), the bronze ceiling of the portico – with nails weighing about 24 kilograms! – was removed. Some 250.000 kilograms of bronze were collected in this way and used for casting cannons for the Castel Sant’Angelo. The claim that the artist Gian Lorenzo Bernini (1598-1680) used the bronze to create the baldachin for Saint Peter’s Basilica is a persistent myth, and so is the story that it was Bernini who added two little bell towers to the Pantheon that became known as the “ass’s ears”. A photo of the towers can be found here. They were more likely designed by Bernini’s rivals Carlo Maderno and Francesco Borromini. The towers were removed in 1883.

Interior of the Pantheon. Note the floor and the three niches behind the columns.

Exploring the Pantheon

Tomb of King Umberto I.

A tour of the Pantheon starts on the Piazza della Rotonda in front of the church. The name ‘Rotonda’ in fact refers to the Pantheon – which was also known as Santa Maria Rotonda – and its circular shape. There seems to have already been a piazza of some sort in front of the Pantheon in Antiquity, at least since the days of Hadrianus, but it gradually became built over during the Middle Ages so that just a narrow street remained. The pronaos of the Pantheon was used as a poultry market during much of the fourteenth century. In the fifteenth century, Pope Eugenius IV (1431-1447) had all the houses obstructing access to the Pantheon demolished and the current piazza laid out. In spite of his efforts, it continued to be used for markets until well into the nineteenth century. The Piazza della Rotonda features a fountain called the Fontana del Pantheon, which was designed by Giacomo della Porta (1532-1602). The fountain had been commissioned by Pope Gregorius XIII (1572-1585) and was completed in 1575. The obelisk was only added in 1711 by Pope Clemens XI (1700-1721). It dates from the reign of the Egyptian pharaoh Ramses II (thirteenth century BCE).

It was the same Pope Clemens XI who had the high altar and apse of the Pantheon remodelled (see the large image above). The job was entrusted to the architect Alessandro Specchi (1668-1729). The architect Paolo Posi (1708-1776) was responsible a restoration of the wall decorations, executed in the late 1740s and early 1750s. In 1870, when Italy had been unified and Rome had become the capital of the new kingdom, the Pantheon was acquired by the State. In 1873, the beautiful floor of the church was restored. Note that this is basically the original floor from Hadrianus’ Pantheon, at least in design. Several of the wall decorations from the lower register, executed in opus sectile, can also be seen as more or less original. The Pantheon has three semi-circular exedrae, one of which is the apse with the high altar, while the other two have been converted from chapels into shrines holding the tombs of Italy’s first two kings, Victor Emmanuel II (1861-1878)[10] and Umberto I (1878-1900). Italy’s third king, Victor Emmanuel III (1900-1946), was not interred here. He had supported Mussolini and was no longer welcome in post-war Italy, although the bronze lamp in the exedra with his grandfather’s tomb apparently burns in honour of him. His son Umberto II ruled for little more than a month; in June of 1946 the Italian monarchy was abolished in a referendum.

Tomb of Raphael.

Apart from the three semi-circular exedrae, there are four exedrae in the shape of a rectangle in the Pantheon. The ones on either side of the apse show that the rectangular exedrae had three niches for smaller statues of gods. The semi-circular exedrae had one large niche each. It seems possible that these held the statues of Mars, Venus and Julius Caesar, while the smaller ones held statues of minor deities. The exedrae have all been converted into chapels, while between them there are several altars. The Chapel of the Annunciation directly to the right of the entrance is by far the most interesting of the chapels. Here we find an impressive fresco of the Annunciation by Melozzo da Forli (ca. 1438-1494), although it is sometimes attributed to his contemporary Antoniazzo Romano (ca. 1430-1510). The other chapels and the altars are not really worth your time.

The most famous person interred at the Pantheon is doubtlessly Raffaello Sanzio from Urbino (1483-1520), known in the English-speaking world as Raphael. His work has been discussed numerous times on this website, for instance here, here and here. The SEPVLCRVM RAPHAELIS SANCTII VRBINATIS – Raphael’s tomb – can be found to the right of King Umberto I’s tomb. His fiancée Maria Bibbiena was also buried here. She was the niece of one of his patrons. The two of them had been engaged for years, but never married. Ultimately Maria died before Raphael did. The artist seems to have been much more interested in his mistress, the lovely Margarita Luti, known as La Fornarina (“the baker’s daughter”). Raphael’s famous portrait of her has also been discussed previously. The text on the sarcophagus in the tomb claims that it contains the OSSA ET CINERES – the bones and ashes – of the artist. It also features an epitaph written by the noted scholar and cardinal Pietro Bembo (1470-1547).


  • Andrea Carandini (ed.), The Atlas of Ancient Rome;
  • Capitool Reisgidsen Rome, 2009 Dutch edition, p. 110-111;
  • Luc Verhuyck, SPQR. Anekdotische reisgids voor Rome, p. 118-125;
  • Santa Maria ad Martyres on Churches of Rome Wiki.


[1] The Life of Augustus 29.5.

[2] The Atlas of Ancient Rome, part 1, p. 508.

[3] Roman History, Book 53.27.

[4] The Atlas of Ancient Rome, part 1, p. 508.

[5] “A violent thunder storm suddenly arose and enveloped the king in so dense a cloud that he was quite invisible to the assembly. From that hour Romulus was no longer seen on earth.” (Livius 1.16).

[6] The Life of Augustus 97.1.

[7] Named after the circus built in 220 BCE.

[8] “Romae instauravit Pantheum”, The Life of Hadrian 19.10.

[9] Atlas of Ancient Rome, part 1, p. 522.

[10] The story that bronze cannons from the Castel Sant’Angelo were molten down to create the large slab for the tomb, and that in this way the stolen bronze returned to the Pantheon, sounds like a myth to me.


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