In front of Bernini’s immense Baldachino over the high altar of St. Peter’s is an area known as the Confessio. This contains stairs leading down to the floor level of Constantine’s first church on the site (the Grotto containing the burials of modern popes from Leo XIII to John Paul II is on the floor of Constantine’s original church). Just underneath the high altar is the Niche of the Pallia, located according to tradition right over Peter’s grave. In the niche is an ancient mosaic of Christ, and an elaborate box where the pallia of Roman Catholic bishops (long strips of cloth made from lamb’s wool) are stored before a bishop’s consecration. This is the oldest part of Saint Peter’s and the religious focus of the whole church. The church’s origins are in the tangled and complex remains concealed behind all the elaborate pious ornament dating from the 17th to 20th centuries.
According to tradition, Peter died in the pogrom ordered by Emperor Nero after a fire destroyed much of the city of Rome in 64, an event that shocked the whole Empire. Nero was a famously incestuous homicidal psychopath, and rumor quickly spread that he had set the fire either for his own amusement or to make room for a new palace. Desperate to deflect blame for the disaster, Nero accused a group of people even less popular than himself, that group of Jewish heretics who refused to worship Rome or its gods and that called themselves Christians. The treasonous, impious, and “godless” Christians were accused of bringing down the wrath of the gods on the city. Nero killed many with tortures of cruelly inventive sadism, but most were probably killed by enraged Roman mobs.
Tradition says that Peter was crucified upside down (at his own request) on the spina of the circus of Caligula just south of the present Basilica. Just as likely, he was one of hundreds killed by the Roman mobs.
The Circus of Caligula was built at the foot of the Vatican hill. Here Nero would scandalize the Roman nobility by driving his own chariot in races rigged for him to win. In the center of the spina of the Circus was a tall Egyptian obelisk from Heliopolis brought back to Rome by Caligula. That obelisk now stands in the center of St. Peter’s Piazza. South and east of the Circus were gardens and a villa belonging to Agrippina, the mother of Nero, and later to the Emperor Domitian. East of the Circus on the north bank of the Tiber was the huge mausoleum of the Emperor Hadrian, now the Castel Sant’Angelo. At the top of the Vatican hill, near where the Sistine Chapel now stands, was a small temple to Attis, the lover of the goddess Cybele. Running just north of the Circus of Caligula was the Via Cornelia, a main road to the port of Ostia. Lining the north side of the road on the slope of the hill was a large crowded cemetery for the poor; for slaves, ex-slaves, and foreigners. It was here tradition says that Peter was buried along with other victims of the persecution.
Street in the Vatican Necropolis
In the 2nd and 3rd centuries, a necropolis for the moderately wealthy was built on top of the earlier poor man’s cemetery. House tombs containing family burials were built close together up the slope of the hill. These were not nearly as large and elaborate as the monumental tombs lining the Appian Way, but they could still be richly decorated. When Constantine leveled this slope to build St. Peter’s, he destroyed all the tombs on the north side and swept their rubble and excavated earth down to the south side, filling up the tombs on the slope to make a level place to build the church. It is these tombs, once above ground, that form the “Vatican catacombs” excavated in the 1940s and 50s. They were mostly pre-Christian tombs with a few identifiably Christian tombs from the 3rd century.
One of the Christian tombs is “Mausoleum M,” also known as the Tomb of the Julii. This tomb contains the earliest surviving Christian mosaics showing scenes from the story of Jonah, and on the ceiling, a combination of Sol Invictus and Christ of the Second Coming showing the syncretic nature of the earliest Christianity. That syncretism would continue in Constantine’s great constructions above the site.
Reconstruction of the Tropaion of St. Peter
The Tropaion photographed during excavations in the 1940s.
Sometime during the 3rd century, the first shrine was built over the traditional site of Peter’s grave, the Tropaion or Trophy. It was a small 2 level structure of marble built into a wall covered with red plaster. It stood in an open courtyard, open to the sky, and accessible by narrow paths and steps down the slope and through the tombs. It was apparently a place of pilgrimage with a lot of visitors. The Tropaion was designed for the early Christian ritual of the celebratory meal at a martyr’s grave; perhaps even for an early form of Eucharist. The small slab in the floor of the shrine is at an askew angle to the shrine itself, perhaps reflecting the original orientation of the grave in the poor man’s cemetery beneath the more affluent later tombs. The courtyard before the Tropaion was crowded with later burials. Accounts of the construction of Bernini’s Baldachino tell of numerous early Christian graves discovered lying in a radial pattern around this central shrine. The shrine itself was rediscovered in excavations ordered by Pope Pius XII.
Emperor Constantine leveled everything around the Tropaion as his first act in building the huge new basilican church. All the tombs up the slope on the north side were demolished. The slope was excavated to make it level with the Tropaion. A large retaining wall 35 feet high was built on the south slope. Rubble and earth from the leveled north side filled the south side slope behind the huge retaining wall. The Tropaion stood alone on top of a huge terrace carved out of the Vatican hill. The new church grew up around it.
Constantine’s new church was one of the earliest of the basilican churches, so-called because they are based on the old Roman basilica, a kind of public building and law court, a building designed for large public gatherings indoors. The old Roman basilica consisted of a long central hall covered by a wooden beam roof, lit by a row of high windows under the ceiling called a clerestory. Flanking that central hall were rows of side aisles. Sometimes on the ends were round exedra where officials held court, the ancestor of the choir or apse of a church. In adapting the basilica to a new religious function, Christians gave the building a focus. An altar was located at one end, drawing all attention to itself. Constantine’s new St. Peter’s was a huge basilican church, the biggest yet built, with 4 aisles flanking a central nave. The walls were covered with narrative mosaics above the colonnades and below the clerestory. There are only fragmentary suggestions of what they once were, but they were apparently extensive cycles from the Genesis narratives and from Exodus together with the Life of Christ, and perhaps of Peter. The broader subject of these narrative mosaics was Salvation History, the central preoccupation of Western Christian art in the centuries that would follow. The apse mosaic, according to records, showed Christ enthroned in Heaven between Saints Peter and Paul.
Constantine’s Church of Saint Peter was the first to incorporate a transept, a huge hall at a right angle to the main hall of the nave. It was located right before the apse. It has been suggested that this was added to give the whole building the form of a cross. More likely, it was built to accommodate throngs of pilgrims coming to see Peter.
Inscribed upon the huge arch separating the nave from the transept hall was “Since under Thy leadership the Empire rose once again triumphant to the stars, Constantine the victor founded this hall church in Thine honor.” Constantine intended it to be a votive offering to the new protective god of the Empire in gratitude for saving it from division and invasion; and, as a memorial to his triumph over Maxentius at the Milvian Bridge.
Constantine incorporated the earlier Tropaion into a new structure that was the focus of the whole church. A carving on a 5th century ivory casket perhaps accurately shows what the memoria in Constantine’s church looked like. A baldachin of marble and porphyry supported by 4 twisted columns from Constantinople rose over the old Tropaion. Two more twisted columns formed a screen in front of the apse. Bernini, alas, did not invent those twisted columns. His own Baldachino over a thousand years later would call to mind this first shrine, only on a gigantic scale. Where exactly the altar was located in relation to this shrine remains a mystery.
Later churches would almost always put the altar in the east. Constantine put the shrine and the altar of St. Peter’s in the West at an angle to catch the first rays of the dawn on the morning of the summer solstice, which came down the full length of the nave to strike the shrine once a year. Perhaps this was another element of syncretism conflating Christ once again with the Unvanquished Sun.
Pope Gregory the Great would dramatically alter Constantine’s original memoria. He raised the whole floor of the apse about 4 feet around the Tropaion. He created the Niche of the Pallia in the Tropaion by altering its 2 level structure. He located the high altar under a new baldachin on top of the old Tropaion. He added another 6 twisted columns from the same late Hellenistic source to form a screen before the shrine. Some scholars speculate that they may have come from a shrine to Dionysus somewhere in Greece or in Asia Minor. They are definitely spolia from a pre-Christian structure. In the Middle Ages, they were commonly believed to have been from Solomon’s Temple, and so the term “Solomonic” endures to describe similar twisted columns. As we shall see, those original Solomonic columns all survive, and were incorporated into the present day church.
There is almost nothing left of Constantine’s great church apart from the fragments embedded in the Confessio. Perhaps the closest we can come to experiencing its original size and splendor is to visit its sister church across town, St. Paul’s Outside the Walls, the traditional burial place of St. Paul. This church is not what it appears to be. It is mostly a 19th century restoration after a fire destroyed most of the original church in 1824. Nonetheless, it is the closest we can come today to something like the experience of walking into Constantine’s original vast basilican church with its walls gleaming with mosaics, lamps flickering around the memoria in the huge apse, and throngs of whispering pilgrims anxiously and fervently praying to the saint resting below.