Historical notes about St. Peter's tomb

South of St. Peter's Basilica, on the ground is a marker designating the place where the obelisk once stood in the circus of Nero. Today this same obelisk is in the middle of St. Peter’s Square. Here, in fact, iuxta obeliscum, St. Peter was crucified upside down, as ancient tradition testifies, and buried in a simple rock tomb in the necropolis that extended a little north along the via Cornelia.

With the construction of the Constantinian basilica the tomb and the surrounding necropolis disappeared from sight and eventually from consciousness. However, both the Constantinian and the present basilica were built in such a way that the papal altar is situated directly over the original tomb, making it the axis for the two massive basilicas that eventually arose over the modest original tomb of Peter. [see diagram of St. Peter's tomb] It is due in great part to Pope Pius XII that the original tomb was discovered and the necropolis excavated during 1940-57. The most important part of the necropolis is the area that contained the body of Peter, called Field P (the archaeologist identified the areas of excavation with letters). It lies in the western section containing many other burial sites from the first and second centuries alongside that of the apostle.

Field “P”

This little area which, in relation to the modern basilica, is directly under the Confession, was called "Field P" by the excavators. It is rectangular in form (about 7 meters from north to south, about 4 from east to west), and it lies in a place where the terrain rises quite rapidly from the south to the north, i.e., toward the Apostolic Palaces, and more gradually from the east to the west, i.e., toward the Vatican Gardens.

Field P is bounded on the west by a wall called "Red" because of the red color of the plaster which was used to cover it; on the south by a tomb which the excavators call “S”; on the east, but only in the southern half of the east section, by another tomb called “O” (this tomb was owned by the Matuccii and is sometimes called by their name). The northern boundary of the eastern side and all the northern boundary of the eastern side and all the northern boundary cannot be traced today, but there are good reasons for believing that there were once structures there which have been mostly destroyed. The most ancient of the tombs surrounding Field P is certainly Tomb O, which, as can be seen form the marble tablet over the entrance, belonged to the Matuccii family. This tomb can be dated about 130, and is certainly later than 123, since a brick was found in one of its walls with a seal dating from that year.

Field P was full of burial tombs. Some of these were brought to light during the 1939-1949 excavations; others, by the successive excavations of the years 1955-1957. These tombs are generally quite modest, situated in the bare ground with little or no protection. Some of them are certainly older than the Red Wall, i.e., before about 160 AD. One of these is the tomb indicated by the excavators with the Greek letter gamma (γ): a child’s tomb which extends partly under the Red Wall, which shows that it must be older than the wall. A precious clue to establish its date comes from a seal pressed into one of the tiles covering it. The seal is dated by scholars at the beginning of the second century (about 115-123), and it is quite probable that the tomb is not much later than this date.

Other tombs in Field P can be dated earlier than the Red Wall. They are usually designated by the Greek letters eta (η) and theta (φ). The first is certainly more ancient than the Red Wall since the two little columns of St. Peter’s Memorial are placed on it, and this monument is contemporary with the Red Wall. The second of these tombs (theta) is under Tomb theta and so, necessarily, earlier. In addition, Tomb theta has, on one of its tiles, a seal that can be dated in the time of the Emperor Vespasian (69-79).

The Red Wall

The Red Wall is so called because of the red color of the plaster (now largely fallen off) which was used to cover it. The essential purpose of the Red Wall seems to have been to fix the boundaries of the various burial places in the area.

About a hundred years after the death of St. Peter, a funerary monument (aedicula), was built against the red plastered wall. A fragment of the red wall was found with Greek graffiti, interpreted by the scholar Margherita Guarducci to say “Peter is here”. This graffito is Greek and it is placed on two lines. The other graffito on the Red Wall, has stayed in place. It is also written in Greek letters and consists in a single line mutilated at the beginning and the end: it seems probable that it was a greeting directed at the Chief of the Apostles.

At its opposite end, to the north, the red wall had been joined by another wall, set at a right angle, suggesting an enclosure. It was clear that a large rectangular area, equal in length to the red wall and about twelve feet in depth, had once stood here free and unoccupied. The entire floor of this open space had been covered by a paving of tiles, white with a green border, laid in part on earth-fill. The focus of this walled-in space, which actually formed a small courtyard, was the two-niched monument built into the red wall, heavy with its travertine shelf.

Before Constantine enclosed the Tropaion (“Trophy”) in his basilica it had been in place on the red wall for at least a hundred and fifty years, though it could well have been nearer two hundred. When it came time to build the Tropaion a century or so after the burial, the orientation of the red wall had to conform to the line and arrangement of the imposing pagan mausoleums now hedging closely round the site. This had forced the red wall to cut directly across Peter’s grave almost at its center, and at a decided angle. It may have been now that the grave was shortened, rather than later, but in any case, it was evident that the builders had taken great care to preserve as much of it as they could, including its alignment on the hillside. They lifted the red wall foundations over the grave in an inverted V, and left standing a remnant of the two low brick walls in their angled position. The closure slab atop the chamber was also preserved intact, twisting away from the red wall at the same eleven degrees. The whole operation bespoke a strong desire not to lose sight of the primitive grave, while fitting the new monument into the surrounding pattern of tombs.

According to the reconstruction, the building has two niches, one above the other, both cut into the Red Wall. Between the two niches, a slab of travertine is inserted horizontally, jutting out, like a table, about one meter from the side of the Red Wall. It is supported by two small marble columns, located in front and on either side of the lower niche. In the floor of the shrine, there is a trap door. It is important to note that the two niches were not indented into the Red Wall after its construction, but were included in its design when it was being built. We can state positively, then, that the chapel’s date is the same as that of the wall, around 160 AD.

Behind the Red Wall ran a small street (the so-called clivus) which slopes up from the south to north and includes some sets of stairs.

On the other side of this clivus are the remains of two other tombs, called R and R1 by the excavators. The clivus gave access to the Tomb R1 and to a tomb called Q which lies behind the Red Wall with the Red Wall itself used for its eastern wall. Under the clivus runs a little gutter used for drainage and covered with a line of tiles, five of which, fortunately, bear a mark by which they can be dated. The mark mentions Aurelius Caesar (Marcus Aurelius) and his wife Faustina as proprietors of the furnace in which the tiles were made. The tiles can therefore be dated between about 146 and 161 AD. It was about 146 when Faustina received the title of Augusta, and in 161 Aurelius Caesar, having succeeded Antonius Pius, took the name of Marcus Aurelius.

In summary, we can say that those who built the Red Wall and its chapel, about the middle of the second century, had the precise intention of marking a place sacred to the Apostle Peter. It has been rightly observed that it would have been simpler to build the chapel beside the Red Wall, instead of laboriously indenting it into the wall. This extra effort shows a desire to indicate with absolute exactitude a place that was considered more precious than any other.

Since the Red Wall was built around 160 AD and Wall G can be dated, through various archaeological and topographical data, around 250 AD, the age of the graffiti on the Red Wall must be between those two dates. One of the graffiti must be considered, at least, earlier than the end of the 2nd century.

Trophy of Gaius

The monument erected above St. Peter’s tomb was in the shape of an aedicule, set against a red plastered wall. There was a niche in the wall, divided into two parts by a horizontal travertine stone tablet, supported at the front by two white marble columns. The aedicule had an opening at its base onto the tomb of St. Peter below.

This was certainly one of the most important discoveries made during the course of the excavations ordered by Pius XII. In fact, a monument already know about in literary sources had been discovered, the Trophy of Gaius. The learned Roman presbyter, Gaius, in fact refers to this construction during the pontificate of Pope Zephirinus (199-217), when, in reply to the heretic Proclo, who boasted of the existence of famous tombs from the apostolic era in Asia Minor, pronounced the following works handed down by Eusebius of Caesarea:

I can show you the trophies of the apostles. If, in fact, you go out towards the Vatican or along Via Ostia, you will find the trophies of those who founded this Church (Ecclesiastical History, II, 25, 6-7).

Graffiti Wall G—the bones of St. Peter

This structure is perpendicular to the Red Wall, built on the right-hand side (north) of the trophy of Gaius during the second half of the 3rd century. The wall gets its name from the surprising amount of Latin graffiti carved into the plaster by the faithful who visited the tomb of St. Peter between the end of the 3rd and the beginning of the 4th centuries. The graffiti includes names, petitions, Christian symbols of complex interpretation and signs superimposed on one another on the reduced surface of the wall. In abbreviated form, St. Peter’s name is present on the wall at least twenty times, usually accompanied by prayers for the dead person named—in one case expressing joy that the lost relative lay in the same cemetery that held Peter’s own body. On every part of the wall—freestanding between the letters of a name, formed from or engrafted onto existing lines—there occurred the initials PE or PET.

At the beginning of the 4th century, a burial niche, internally covered in marble slabs, was built into the depth of Wall G. During the excavations of 1941, bones were found inside the niche of Wall G. Initially these were not though to be the bones of St. Peter, and they were simply stored away in the Grottoes for many years. Later, Margherita Guarducci, who was researching the graffiti of Wall G, had the bones examined. Prof. Venerando Correnti, of Palermo University, one of Europe’s most distinguished anthropologists, made a full-scale anatomical study of the bones now widely believed to be those of the apostle.

Margherita Guarducci sums up the case for these bones being those of St Peter as follows:

• The Constantinian monument was considered, in Constantine's day, to be the tomb of the martyr.
• Inside the monument-sepulcher there exists a loculus, and one only: the loculus of Wall G.  This loculus was carved out of Wall G and lined with marble at the time of Constantine. The loculus was never broken into from the age of Constantine until the time of the excavations (about 1941).
• From this loculus come the bones which were removed at the beginning of the excavations, kept without interruption in a nearby spot in the Vatican Grottoes and recovered from this spot in 1953. These bones, therefore, are the ones which were verified at the time of Constantine as the bones of Peter and place in the loculus of Wall G, inside the monument-sepulcher.
• The cloth of purple interwoven with gold-thread in which the bones were wrapped at that time confirms the highest dignity then attributed to the remains.
• The anthropological examination of the bones—belonging to a single individual—showed that they conform perfectly to what, by tradition, we can imagine was Peter’s physical appearance at the time of his martyrdom. Apart from the obvious fact that they belong to a male, the bones indicate a sturdy build and an age somewhere between 60 and 70.
• The earth encrusted on the bones indicates that the bones themselves originally lay in an earth—grave, and we know that Peter’s first burial was in the earth. The characteristics of the earth, shown by the scientific examination, match those of the place where the original tomb was dug (marly sand), while in other parts of the Vatican area the earth is different (blue clay or yellow sand).
• The place of the earth-burial under the Trophy was found empty. This is in harmony with the presence of the bones, transferred about two meters higher up, in the loculus in the monument of Constantine.

watch an excellent video on the evolution of St. Peter's tomb >

Bibliographical references

Much of the material quoted above is taken from www.saintpetersbasilica.org, complemented with the bibliography listed below.

BASSO, Michele. Guide to the Vatican Necropolis. Vatican City: Fabbrica di S. Pietro in Vaticano, 1986.

GUARDUCCI, Margherita. The Tomb of St. Peter. Hawthorn Books, 1966.

TOYNBEE, J. – PERKINS, J. W. The Shrine of St Peter and the Vatican Excavations. London: 1956.

WALSH, John Evangelist. The Bones of St. Peter. New York, 1982.

ZANDER, P. The Vatican Necropolis, in "Roma Sacra", 25. Rome: 2003.