The Pantheon, a temple for the worship of all Rome's gods (pantheon translates as 'all gods’), was constructed by the Emperor Hadrian between AD 118 and 125 in the Campus Martius, a brown-field site on which two earlier buildings had stood, one of them built by Agrippa in 27 B.C.
The inscription over its portico records Agrippa as its builder (M. Agrippa L. f. consul ter(tium) fecit), but close examination of the structure reveals this to be untrue. So why the lie? The likely answer is that Hadrian needed to improve his public and political image by putting up a few grand public buildings, but could not afford to have Rome think of them as monuments to his own vanity. He needed a public demonstration of modesty.
Hadrian had become unpopular because he was hardly ever home. To Romans, Hadrian seemed to prefer travelling the empire - even Britain (which he visited in AD 122 and where he built a wall). And reports of what he got up to when he was abroad did not go down well back home. People were scandalized by rumours that he was worshipped in the east as a living God. The result of this poor press was the need for some good PR.
The Historia Augusta, a collection of biographies from the 4th century AD, records that Hadrian '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. 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'.
At the end of the aisles of the Pantheon were two niches in which were two statues, one of Agrippa and one of the first, and model emperor, Augustus. There was no statue to Hadrian.
The temple comprises a porch (Pronaos) and a rotunda topped with a dome that forms the cella of the temple. The dome is a perfect hemisphere, and it was the largest dome in the world until Brunelleschi built the dome of Florence Cathedral in 1420-36.The immense size of the dome required high-spec building materials, and so sophisticated mixes of aggregates were used to create super-strength and super-light concretes. The foundations were made with travertine (the heaviest aggregate) and the top of the dome, around the oculus or circular opening in the roof, was made with volcanic pumice (the lightest) with four other materials of graded weight used between them. This meant that the dome would not become top heavy and fall in on itself. The weight of the dome was distributed, via many large brick relieving arches within the walls, on to each of the eight load-bearing piers which form the framework of the temple. Within each of these piers was set a statue of one of the Gods.
Later the temple was given to Pope Boniface IV by the Byzantine Emperor Phocas in AD 608 who turned it into the church of Santa Maria ad Martyres, this ensured the building's survival but resulted in alterations including the addition of two turrets, now removed, and the replacement of the statues of the old gods with Christian works of art.(Next)
Top: View of the Remains of Ancient Buildings in Rome, and its vicinity.London, 1820.
Middle: Le antichità romane.Rome, 1756.
Bottom: Le antichità romane.Rome, 1756.