Scavi (Excavations under St. Peter’s Basilica)

Two weeks ago Wednesday, Msgr. Ray Dreiling (Fresno CA) and I went on a tour of the Scavi, the Excavations under St. Peter’s Basilica. I read up on the subject after the tour, which gave me pause after experiencing one of the holiest sites of Christianity.

The present Basilica of St. Peter’s began construction in the late 15th century and was completed in the 17th century, under the direction of twenty popes and ten different architects they sent to work on the project. From what I remembered of the tour, the tour guide explained how over the centuries, generations of Christians believed the main altar of St. Peter’s was built over the tomb of the Apostle. But no one had any documented proof that established the fact. What was uncovered when Pope Pius XII ordered the excavation under the main altar in the 1940s simply confirms those dearly-held beliefs. The oral tradition indicates Peter suffered crucifixion upside-down in the circus of Emperor Nero, and was buried in a necropolis (literally, city of the dead, a graveyard with individual plots for the ordinary folks and mausoleums for the wealthy) outside the walls of the city, for hygienic reasons. Over time, the locals built a monument above the grave they believed was Peter’s. But still there was no written record, no grave marker, no external sign that definitively pointed to the holy site in question. When the Emperor Constantine in the 4th century decided to acknowledge the growth of Christianity by declaring it a valid practice of religion, he leveled the Vatican Hill and built a wooden basilica over the spot recognized as Peter’s grave. Previously there was a simple monument to mark the spot. Everything higher than the spot recognized as Peter’s grave was leveled. Everything lower was buried in earth. So when the area under the current basilica was excavated, what had been buried in earth had been perfectly preserved. We were not allowed to take pictures, but we saw mosaics, frescoes, and bass reliefs that depicted Christian themes. It seemed Christians were buried alongside non-Christians, without distinction within the same mausoleums.

Pius XII, to honor his predecessor Pius XI, had ordered the excavation in the crypt (a level below the current basilica’s floor) to make room for a monument prepared for the deceased pope. But when the excavations yielded inconclusive evidence, attempts were made to establish the site of Peter’s tomb. Eventually, the remains of a simple structure were discovered under the high altar. And in a niche in a wall were found some bone fragments, with graffiti indicating “Peter is here.” The Pope decided then to halt further excavation. The bone fragments were collected in a box and replaced in the niche, a bit of it visible behind the Clementine Chapel in the crypt.

It is amazing that the faith of a simple Galilean fisherman from 2000 years ago would be the rock on which a worldwide church would be built. The current basilica in all its grandeur stands as evidence of a people’s faith. They didn’t need written documentation or external markers lest they forget the sacred spot. They knew in their hearts. And 2000 years later, built on the same rock of faith, the church still stands.

The high altar stands under the baldachino (canopy) of Gian Lorenzo Bernini, above the spot believed to be the grave of St. Peter the Apostle.

The basilica built by the Emperor Constantine above the Apostle’s grave, after leveling the Vatican Hill.

Floor levels beneath the current Basilica of St. Peter. The crypt is the level below the basilica’s floor. The floor below it is the necropolis.

An artist’s rendering of the first simple structure to mark the Apostle’s grave. Bone fragments were found in a niche of the red wall, and graffiti on the wall indicating “Peter is here.” The bone fragments were collected in a box and replaced in the niche, which lies directly beneath the high altar.

A simple plan of the necropolis beneath the basilica of Constantine. The bone fragments found toward the left of the diagram in the left wall of the area “P” known as the tropaion are believed to be of the Apostle.