Who built St Peter’s? Books and web sites invariably credit Constantine     . But why? The histories of the time are silent. One book, St. Peter’s in the Vatican, critiqued the sources for this conclusion.
- Inscriptions in old St. Peter’s
the monastery of Einsiedeln had a collection of inscriptions recorded before the ninth century. One was from the triumphal arch inside old St Peter’s. It said
Because under your leadership the world in triumph has risen to the stars, victorious Constantine has founded this hall for you. In the fifteenth century, you could see the worn inscription,
Of Constantine … a hostile incursion … expiated, on another arch. So at some point, there were inscriptions lauding Constantine in old St Peter’s. As there were in other churches and places he had little or nothing to do with.
- Later popes
the Liber Pontificalis, the book of the popes, came into being two hundred years after Constantine. It says that he built St Peter’s. And what else? Constantine was baptised by Sylvester, the bishop of Rome then (earlier sources say he was baptised in the east by the Arian bishop Eusebius) and that the church was built over a temple of Apollo (digs in the 40s and 50s showed it was built over a cemetery and around a pre-existing shrine to Peter).
- Helena’s gift
the Liber Pontificalis also describes a gold cross that topped the tomb of Peter within his church. It was inscribed
Constantine Augustus and Helena Augusta, they adorn with gold this royal house, which the hall surrounds, gleaming with a comparable radiance. Helena was Augusta after 324 and dead by 329. But was the cross originally in St Peter’s? How could the tomb be considered a royal house? Was the cross taken from the chapel Helena kept in the Sessonian Palace, her royal house in Rome?
Accounts crediting Constantine even give dates, 319 or 322 or 333.
- The Great Mother says 322 or 333
the Phrygianum was the temple of the Great Mother on the Vatican, the area’s most significant holy site before St. Peters was built. In 1919, an undated inscription was found near St. Peter’s which stated that her rites had been halted for twenty eight years. Before 370, we have only two dated inscriptions from the Phrygianum, one from 305 and one from 350. If the cessation was caused by the building of St Peter’s and it fell between 305 and 350, then we get two dates, one forward of 305 (333) and one before 350 (322), both within the time of Constantine. BUT who says the cessation was due to construction work or even had to fall between those dates?
- The law says 333
according to the Theodosian Code, in 349, one of Constantine’s heirs, Constans, issued a decree threatening severe punishment for tomb violation and made its application retrospective for sixteen years. St Peter’s was built over a cemetery so it must have prompted this law. Go back sixteen years from 349 and you get 333. But the Theodosian dates and attributions are unreliable. Some ascribe the law to Constantius in the east. And again, there is no mention of St Peter’s.
- A pristine coin says 319
diggers found a coin from 317 or 318 in an undisturbed level of the cemetery below the basilica
So what was there in Constantine’s time? Eusebius wrote much about his emperor’s church building but never mentioned a church for St Peter. He did however mention that Peter had a shrine on the Vatican. First in his Church History where he records Gaius, an early third century Christian Roman, saying that there were
trophies of Peter on the Vatican and Paul on the Ostian Road. Then in his Theophany, he describes
a great temple and sanctuary of God for Peter. Both references capture the shrine and forecourt found during the excavations under St Peter’s (they found a drain dating back to 160).
And who built the church? Brick stamps of the original apse, found in the early 17th century, read
d n constant aug. Genitive for Constant points to his son, Constans, who ruled the city of Rome after his father’s demise. And an inscription in the Einsiedeln monastery’s collection thanks a son:
renders the one who made it equal in glory to his parent. So maybe Constans. Maybe in competition with his brother, who ruled the east, busy building the Holy Sepulchre and other signs of his piety.
Maybe, only maybe. Like so much about then, we don’t know.