The Mysterious Pantheon
By: TammyJo Eckhart, PhD on 4/15/2019


At the end of April 2019, Rome Reborn® will release “The Pantheon” as a new app that allows us to see what it likely looked like in 320 CE when it was still being actively used and protected by Romans. While this essay is meant as a general introduction, it looks at some complex issues that historians are still working through today. My main point will be to stress the irony that this best-preserved of Rome’s ancient buildings has also been one of its most enigmatic.

In many mainstream history books or guides, we are told that the Pantheon was built between 27-25 BCE during the reign of Augustus. But the Pantheon, as presented in most modern accounts and in Rome Reborn® app, is really the second Pantheon. The fact that the structure had two phases is our first enigma and can be confusing. When you look at the dedicatory inscription, you read:  M AGRIPP L F COSTERTIVM FECIT (Marcus Agrippa, the son of Lucius, three times consul, built this.) Marcus Agrippa was Augustus’ supporter and son-in-law; he was consul for the third time in 27 BCE. So, the building we’re looking at must date from that year, right?

Ancient authors such as Dio Cassius wrote that the Pantheon was indeed from the time of Augustus. Until the late 19th century no one doubted that this best-preserved of ancient buildings in Rome should, in fact, be dated to the time of Augustus. What happened to change this unquestioned consensus? Georges Chédanne, the winner in 1887 of the Rome Prize in Architecture from the French Academy in Rome, discovered some brickstamps dating to the reign of Hadrian. That changed everything: now scholars realized that they needed to rewrite their Roman architectural history and move the Pantheon from the chapter on the Augustan age to the Hadrianic.

Research of the ancient sources showed why we should always have suspected something of the sort. Pliny the Younger tells us that the Emperor Hadrian rebuilt the Pantheon and there is confirming physical evidence that there were fires in this part of Rome in 80 and 110 CE.  They destroyed much of the earlier building, thus making it necessary for Hadrian to come to the rescue and rebuild the temple. This idea of the Pantheon as a rebuild is important because it helps us understand the temple, its location, and its meaning. An inscription beneath the Agrippa plaque states that the structure was restored again in 202 CE by the Emperor Septimius Severus and his son Caracalla, showing that the Pantheon remained important and worthy of maintenance.

The location of the Pantheon, aligned with and the same size as the Mausoleum of Augustus sited directly to the north, suggests a strong connection to the first emperor of Rome. It could be that Hadrian wanted to be associated with Augustus through the Pantheon, and indeed, the similarity of the two emperors’ mausolea is more concrete evidence of this desire. Hadrian is also credited with rebuilding the Baths of Agrippa directly south of the Pantheon, again tying himself to the Augustan era. Hadrian, of course, had a massive building and rebuilding program in Rome and all over the empire (definitively treated in the books of Mary T. Boatwright), so his projects in this part of Rome is not at all surprising. Equally unsurprising is the fact that he did not replace Agrippa’s name on the dedicatory inscription with his own: his ancient biographer tells us that this was his common practice when restoring an earlier monument: “ He built public buildings in all places and without number, but he inscribed his own name on none of them except the temple of his father Trajan” (Historia Augusta, Vita Hadriani, 19).

Ancient sources mention that statues inside the Pantheon included Julius Caesar, Venus, and Mars, as well as Augustus and Agrippa outside it. For the first emperor of Rome, these connections to the gods would have been personal. Caesar claimed descent from the goddess Venus, and he himself was deified after his death. Mars and Venus had been connected romantically since the influx of Hellenism with its tales of Ares and Aphrodite. Mars, too, was an old god in Rome, second only to Jupiter, and was the legendary father of Romulus and Remus.

Its name, along with the fact that statues of the gods were placed inside the apse and the six alcoves of the rotunda of the Pantheon, might make you think that figuring out its religious function would be easy. As the name implies, it was a “temple to all the gods,” right? This is our second big enigma. In modern usage, a pantheon can simply refer to the collection of entities that any people worship, but those entities can be gods or just famous people (for an example of the latter, compare the Panthéon in Paris, and our building itself served, in part, this function if we think of the burials here of notable figures such as Raphael and the first two kings of modern Italy). In the ancient world it could be seen as the home (temple) to all gods or to particularly important gods, and there certainly were temples to multiples gods throughout the Roman and Greek world.

Another interpretation of the structure is that it is a representation of the heavens or the world. Generally, this is because of the dome and the oculus at the center, as well as the reported designs on it of heavenly objects. The shape of the building — rectangular forecourt, round building — is also argued to be symbolic. If these ideas are correct, then Hadrian’s rebuilding and reimagining of the Pantheon might indicate that Rome was presenting itself as the center of the world and the heavens. Some scholars believe other statues inside represented gods connected to the heavens such as Jupiter and Saturn, but again, where is the solid evidence?

If the statues represented the gods, heavenly bodies or not, the fact that new rulers of Rome might place themselves and family members as models for them indicates that they wanted to be strongly associated with the gods and the world. While Octavian (Augustus) may not have claimed divine status during his lifetime, he actively worked to have it bestowed on his adoptive father Julius Caesar, and Augustus himself received it after his death. Other members of his dynasty claimed godhood (Caligula) and allowed foreigners to dedicate religious rites and buildings to them (Claudius). Successive imperial dynasties followed suit, so recasting statues in the Pantheon may be a simple continuation of that trend. Some modern scholars who accept this interpretation of the Pantheon see it as a kind of gateway to this part of the northern Campus Martius, which is so filled with monuments commemorating deified members of the imperial family, whether we think of the ustrinum of Augustus or of Marcus Aurelius, the Column of Marcus Aurelius, the Porticus Divorum (the “divi” are Vespasian and his son Titus), the Temple of Matidia (Hadrian’s mother-in-law), or the Temple of Hadrian.

Finally, we should consider when the two phases of the Pantheon were created. Both the Agrippan and Hadrianic temples came at a time of “Roman Peace,” which had been achieved not through creation of a harmonious, Romanized society from one end of the empire to another, but through Roman military might and political acumen. In the 20s BCE, Rome had recently been through a period of political strife climaxing with Augustus’ defeat of Antony and Cleopatra. Later, Trajan, then Hadrian, consolidated power a second time after a period of civil war following Nero’s death and the assassination of Domitian, which brought the Flavian dynasty to a crashing conclusion. Externally, the imperial armies enforced Rome’s will, and the massive building projects of both Augustus and Hadrian showed the power and incredible material resources of Rome. In this sense, the Pantheon could be a symbol of the power of Rome itself. Even in 357 CE, soldier and author Ammianus Marcellinus believed the Pantheon still proved the centrality of Rome to the entire world.

The Pantheon was important enough that centuries later, in 609 CE, Pope Boniface IV rededicated it to the Virgin Mary and the Martyrs. Despite what we, as lovers of Roman antiquity, might find to be a rather presumptuous and inappropriate move, this actually turned out to benefit the Hadrianic structure, because by transferring the dedication from the ancient Roman gods and defied rulers to the faithful who suffered death on behalf of the Christian faith, it gave Rome’s Christian rulers an incentive to preserve the building against the spoliation which would otherwise have predictably occurred in the long period stretching from the Middle Ages to the Risorgimento.

What did the Pantheon represent? Given the evidence of what was inside, how often it was rebuilt or repaired, and who claimed connection to it, it was important to generations of Romans, ancient or Christian. But what happened in it beyond Hadrianic ceremonies and Christian rites? We simply do not know with certainty. Sometimes, that lack of certainty is something we must simply accept when we look into the ancient past. Yes, it can be frustrating but, to end on a bright note, it can also stimulate our imaginations and motivate new research.



Boatwright, Mary T. Hadrian and the City of Rome. Princeton University Press. Princeton, NJ 1989.

Boatwright, Mary T. Hadrian and the Cities of the Roman Empire. Princeton University Press, 2000.

La Rocca, Eugenio. “Agrippa’s Pantheon and Its Origin,” in The Pantheon. From Antiquity to the Present. Edited by Tod A. Marder, Mark Wilson Jones. Cambridge University Press, New York, 2015, pages 49-78.

Macdonald, William Lloyd. The Pantheon: Design, Meaning, and Progeny. Harvard University Press, Cambridge, MA, 1976.

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