If we were to walk along the narrow alleyway 70 meters long that separates two rows of burial stones—mostly dating from the second century—it would be as though we were taking up the dare once made by the ecclesiastical writer Gaius. Writing at the close of the second century to the heretic Proclo, Gaius challenged him in these words: “I can show you the memorials erected to the apostles, because if you go to Vatican Hill or to the Via Ostiense, you’ll find the memorials of the founders of this Church.” He was speaking, of course, of Peter and Paul. The memorial to Peter is located seven meters below the papal altar in St. Peter’s Basilica.
There, in the center of a quadrangular area measuring four meters by four, dubbed “Field P”by archaeologists, the humble tomb of the Apostle was dug sometime during the sixth decade of the first century. According to tradition, a terebinth tree originally marked the spot where Peter was buried. Around the year 160, a wall was erected next to the sepulchre (called “the red wall” because of the color of its plaster), separating this burial spot from other parts of the necropolis.
Next to it, a small monument was constructed. It consisted of a slab with two niches, one above the other, divided by a marble shelf supported by two small columns 80 centimeters high. The combination of the two—the slab with its niches and the “red wall” against which it was built—must be what Gaius was referring to with his talk of “memorials”. Dating from slightly after the middle of the second century, the structure is exceptionally important.
We know it was the most venerated part of the burial ground. The “red wall” and the modest memorial within “Field P” testify to the wish, as early as the middle of the second century, to conserve and integrate an earlier tomb within the context of an expanded necropolis. And this took place, we should bear in mind, in spite of the extra care that Christians had to take at a time of ferocious persecution.
In order to protect the mortal remains of the Apostle from repeated accumulations of mud and earth, another wall was placed perpendicular to the “red wall”. This was named by archaeologists “Wall G” (for Graffiti) because of the numerous messages etched onto the plaster. The invocations to Christ, Mary and St. Peter speak eloquently of the devotion of the first pilgrims.
In a small loculus carved out of “Wall G” and paved with slabs of marble, were deposited what was left of Peter’s mortal remains after having been buried for nearly two centuries in the earth.
The fact that all of this was cared for and watched over, even within the context of a constantly expanding necropolis, means that it was a place of veneration from the earliest times. Peter was there. The Emperor Constantine and Pope Sylvester were so sure of it as to encapsulate the whole in a larger monument of white and purple marble with slabs of red porphyry. Built into it was a passageway that allowed one to approach the tomb of the Apostle.