Tomb of St Peter Under the Vatican

1. What the Scavi Are

The Scavi are the excavated remains of a Roman cemetery lying under the floor of St Peter's Basilica in Vatican City, opened by archaeologists working for Pope Pius XII between 1940 and 1949. The Italian word scavi means excavations, and it has become the ordinary English name for the site. Running through the middle of that cemetery, directly under the papal altar and the dome, is a small niched monument of roughly the year 160 that Christians of the second century treated as the grave of the apostle Peter.

Everything argued about the tomb of St Peter starts from that one physical fact. A cemetery on a hillside outside ancient Rome contained a modest shrine. Two centuries later an emperor spent an enormous sum burying that entire hillside in order to build a basilica whose altar sat exactly over the shrine, and every basilica since has kept the same point. The building has moved around the grave. The grave has not moved.

The question this page answers is the evidence question. Is the apostle Peter really buried under the Vatican, and do the bones the Vatican holds belong to him? Those are two separate questions with two different strengths of answer, and the popular retellings tend to collapse them into one. The interior of the church above, the baldachin, the Pieta and the confessio rail where pilgrims kneel, belongs to the guide to St Peter's Basilica and what to see inside it. This page stays underground.

2. Why Anyone Dug Under the Basilica

The excavation began by accident, and by a burial. Pius XI died in February 1939 and had asked to be buried in the grottoes, the low chamber under the basilica floor where popes are laid. To make room, workmen began lowering the grotto floor. They ran almost immediately into Roman masonry, the tops of mausolea that Constantine's engineers had filled with earth and sealed sixteen centuries earlier.

Pius XII, elected the following month, authorised a full excavation and kept it quiet. The work ran from 1940 to 1949, through the Second World War, in cramped conditions under the weight of the basilica overhead, with the water table close and the piers of Michelangelo's dome standing on the ground the diggers were tunnelling beside. Monsignor Ludwig Kaas, administrator of the Fabbrica di San Pietro, held overall charge of the site. The archaeological direction lay with the Jesuits Antonio Ferrua and Engelbert Kirschbaum, with Enrico Josi and the architect Bruno Maria Apollonj Ghetti. Their report appeared in 1951.

The names, the dates and the sequence above follow the official excavation report, Esplorazioni sotto la confessione di San Pietro in Vaticano, published by the Vatican in 1951, and the accounts subsequently given by its authors. This page reports the published findings and the disagreements about them, and asserts no independent archaeological judgement of its own.

A Divided Command

One feature of the dig matters for everything that follows. Kaas was a churchman with a pastoral concern for the bones of the dead, and he made a practice of walking the site in the evenings with a workman, collecting human remains that had been left exposed and having them stored respectfully in boxes. The archaeologists wanted material left in place and recorded. The friction between the two habits produced the single worst problem in the whole affair, which section 9 comes to: the most important bones on the site were lifted, boxed and shelved before anyone recorded exactly what they were.

What They Were Looking For

The excavators had a text in mind. Around the year 200 a Roman presbyter named Gaius, arguing with an opponent about where apostolic authority lay, said that he could point to the trophies of the apostles: Peter's on the Vatican, Paul's on the road to Ostia. Eusebius of Caesarea quotes the passage in his Ecclesiastical History (2.25.7). The Greek word is tropaion, a victory monument, used here of a martyr's memorial. Gaius was inviting a sceptic to come and look at a physical object. The diggers of 1940 were going to see whether that object was still there.

3. The Buried Street of Tombs

What the excavation opened first was an ordinary Roman cemetery of the imperial period, remarkably well preserved because Constantine's fill had sealed it. A narrow street runs east to west along the slope of the Vatican hill, lined on both sides with family mausolea built of brick, roughly two dozen of them along the excavated stretch of street. They are small houses for the dead, with doorways, name inscriptions over the lintels, stuccoed and painted interiors, niches for cremation urns and, in the later ones, floor graves for burial.

The families are mostly pagan and mostly of the freedman and middling classes, the sort of Romans who could afford a decent tomb and wanted their names read from the street. The Caetennii, the Valerii and the Tullii have some of the grandest. Painted stucco, mosaic floors, portrait busts and terracotta reliefs survive in good condition because these rooms were never open to weather or looting after the fourth century. Read on its own terms, without the basilica above it, the site is a Roman cemetery that was sealed rather than weathered, robbed or rebuilt.

The Vatican Hill in the First Century

The ground here lay outside the city proper, across the Tiber, in the district the Romans called the ager Vaticanus. It held gardens, a circus begun under Caligula and used by Nero, and this roadside cemetery on the slope above. Roman law required burial outside the inhabited city, so cemeteries lined the roads out. The tall red granite obelisk now standing in the middle of St Peter's Square was brought from Egypt by Caligula and set on the spine of that circus. It was moved to its present position in 1586 under Sixtus V. It is the one large object in the piazza that was standing in Rome in the first century, and it stood a short distance from the ground under discussion here.

The Christian Mosaic in the Tomb of the Julii

One mausoleum, labelled M by the excavators and belonging to the Julii, has a vaulted ceiling covered in gold-ground mosaic with vine tendrils, and figural panels showing Jonah thrown to the sea creature, a fisherman with a line, a shepherd carrying a sheep on his shoulders, and on the vault a beardless figure in a chariot with rays about his head. The reading generally given is that the charioteer is Christ presented under the visual language of Sol, the sun. The mosaics are usually dated to the third century, which would make them among the earliest Christian mosaics known in Rome. Some scholars have argued for a purely solar reading of the vault figure, so the interpretation carries a genuine question mark, while the Jonah and shepherd panels beside it are standard early Christian subjects.

The mixed character of the cemetery is itself part of the argument. A Christian buried here in the first century would have been buried in a public roadside cemetery among pagan neighbours, which is exactly what would happen to a man executed under Nero and taken away by fellow believers who had no burial ground of their own.

4. The Aedicula and the Trophy of Gaius

In the middle of the street of mausolea the excavators found an open plot they labelled Field P, and against its rear wall a small monument. The wall is faced in red plaster and is known in all the literature as the Red Wall. Set into it is an aedicula: a niche at ground level, a second niche above it, and a small travertine slab carried on two little marble columns projecting over the lower niche. Nothing about it is grand. It is a modest memorial in a public cemetery, the kind of thing a community with no money and some risk would build.

Directly under this aedicula, and only under this aedicula, sits the high altar of the basilica, the baldachin, and the centre of the dome, at a distance of several metres straight up. The alignment is exact, and it was achieved at great engineering cost by four successive generations of builders.

How It Is Dated

The Red Wall carries brick stamps that place its construction in the middle of the second century, in the years around the reign of Antoninus Pius, and a drain running through the plot belongs to the same phase. The aedicula was built into the wall as part of that work or immediately after it. A date of roughly 150 to 170 is the standard one. That is the same generation in which the Roman church was already telling visitors that Peter lay on the Vatican, and it is about forty years before Gaius offered to show his opponent a trophy.

The Ground Under the Shrine

The excavators reported that the ground in Field P contained simple earth graves older than the Red Wall, and that the builders of the aedicula placed its foundations so as to avoid disturbing the ground immediately beneath the lower niche. Beneath that niche they found a grave cut into the earth, which they labelled with the Greek letter gamma, its contents disturbed and incomplete. Later burials in the surrounding plot are crowded toward the aedicula, packed in at awkward angles as if to lie close to it, the same behaviour seen around martyrs' graves in other Roman cemeteries.

The plainest reading of that stratigraphy is the one the excavators gave. Someone was buried in this modest plot before the middle of the second century. The spot was remembered. A memorial was then built over it with care taken not to disturb what lay below, other Christians paid to be buried nearby, and by the year 200 a Roman priest was inviting sceptics to come and look at it.

5. The Red Wall, Wall g and the Graffiti

The Red Wall developed a crack, and about the year 250 a buttressing wall was built hard against it beside the aedicula. The excavators labelled that wall with the letter g, and it is called the Graffiti Wall because its plaster is covered with scratched Christian inscriptions: names of the dead, invocations, acclamations to Christ and to Peter, monograms and crosses, layered over one another in the way that graffiti accumulates at a place people come to pray.

Graffiti of this kind is strong evidence of cult. People do not scratch prayers on a random garden wall. They scratch them where they believe something is, and they scratch them in numbers over time. Comparable walls survive at other Roman martyr sites, and their message is the same: this spot was visited, by many people, for generations, for the sake of what was in the ground.

The Loculus in Wall g

Inside Wall g, at the point where it meets the aedicula, the excavators found a rectangular cavity lined with marble slabs, a loculus, closed and containing bone fragments mixed with earth. The cavity was opened in 1942. Its contents were removed and stored, and the removal was not recorded with the care the excavators were applying elsewhere on the site. The bones went into a box in a storeroom and stayed there. Section 9 follows them.

The Contested Inscription

A fragment of plaster from the Red Wall beside the aedicula carries scratched Greek letters that can be read as Petr and eni. Antonio Ferrua, one of the original excavators, published the fragment. Margherita Guarducci later completed and interpreted the text as Petros eni, meaning Peter is within, or Peter is here. Ferrua himself did not accept that reconstruction, and other epigraphers have argued that the broken fragment will not bear the weight placed on it. Popular accounts often quote Peter is within as though it were an undisputed reading. It is a disputed reading, and the case for the site does not depend on it.

Guarducci also proposed that much of the graffiti on Wall g works by a system she called mystical cryptography, in which letters and monograms encode compressed acclamations to Christ, Mary and Peter. That proposal has not been generally accepted by epigraphers, who read most of the marks as names, abbreviations and conventional invocations. The disagreement matters for how much weight her later conclusions about the bones can carry.

6. Did Peter Die in Rome?

The archaeology sits on top of a prior historical question, and that question has an unusually clean answer. Every surviving ancient source that says anything about where Peter died says Rome, and no surviving ancient source proposes anywhere else. Ancient cities competed hard for apostolic graves, so the total absence of a rival claim is significant.

The New Testament does not report Peter's death. The Gospel of John records the risen Christ telling Peter that when he was old he would stretch out his hands and be led where he did not wish to go, and the evangelist explains this as an indication of the death by which Peter would glorify God (John 21:18-19). The First Letter of Peter closes with greetings from the church in Babylon (1 Peter 5:13), which Christian readers from the second century onward have taken as a code name for Rome, the reading Revelation also uses.

The Chain of Early Witnesses

Outside the New Testament the line is continuous. The First Letter of Clement, written from the Roman church in the last years of the first century, speaks of Peter and Paul as pillars who suffered and went to the place of glory, and addresses the Corinthians as though these were recent events known to both cities (1 Clement 5). Ignatius of Antioch, writing to the Romans early in the second century on his own way to execution there, tells them he does not command them as Peter and Paul did, which assumes an established relationship of those two apostles with that church. Irenaeus of Lyon, around 180, says the Roman church was founded and organised by Peter and Paul and gives a succession list of its bishops (Against Heresies 3.1.1 and 3.3.2). Dionysius, bishop of Corinth, writing about 170 in a letter Eusebius preserves, says the two apostles taught in Italy and were martyred at the same time. Then comes Gaius with his trophy.

Tacitus, a pagan historian with no interest in assisting Christians, supplies the setting. He records the persecution Nero launched after the fire of 64, the executions carried out with deliberate cruelty, and the use of the emperor's gardens and circus on the Vatican for the spectacle (Annals 15.44). He names no Christian. He puts a slaughter of Christians on precisely this hillside within the generation of the apostles.

The Honest Weak Points

Two things should be conceded. No first-century source states in plain words that Peter was executed at Rome under Nero, and the vivid details most people know, including the crucifixion head downward, appear later. Origen is the source for the inverted crucifixion, quoted by Eusebius, and the apocryphal Acts of Peter supplies the scene most of the artwork depends on. Those are traditions of the second and third centuries rather than eyewitness reports, and honest Catholic scholarship says so.

What survives that concession is still a great deal. Multiple independent Christian witnesses from three different regions within a century of the event, no competing claim from any rival city, a pagan historian placing a mass execution of Christians on this hill in the right decade, and a purpose-built memorial in that ground by about 160. For Peter's life, his calling, his failure and his commission, see the guide to Simon Peter, the fisherman given the keys, and for the office traced from him, the guide to the papacy.

7. What Constantine's Builders Did

One of the strongest pieces of evidence for the tomb is the behaviour of the men who buried it. In the fourth century Constantine's engineers chose to build a five-aisled basilica on the side of a hill, which meant cutting away the slope on the north, raising a massive retaining platform on the south where the ground fell away, and filling an entire working cemetery with earth and rubble to the roofs of its tombs.

The cost was enormous and the site was bad. Level ground was available nearby. Roman law and Roman feeling both protected tombs, and violating a cemetery on this scale required an emperor's authority and gave offence. The builders did all of it in order to put the altar of their church on one specific square metre of a second-class graveyard.

The Constantinian Monument

They also treated the aedicula itself with striking care. Rather than clearing it, they encased it in a box of marble and porphyry, leaving it standing in the fill at the level of the new basilica floor, and set the altar over that box. Every later altar has repeated the gesture. The altar of Callixtus II in the twelfth century was built over the Constantinian monument, and the altar of Clement VIII at the end of the sixteenth century was built over that, so that three altars now stand stacked one inside another above the shrine, with Bernini's bronze canopy over the top of them.

What Happened to the Grave Below

The care went to the monument. The ground under it fared worse. Centuries of building, of water in the fill, of medieval repairs and of the demolition and reconstruction that produced the present basilica left the earth around and under the aedicula disturbed. When the excavators reached it they found bones scattered through the fill, graves cut into by later work, and no undisturbed burial lying in place beneath the shrine. That is the physical situation from which every later argument about specific bones has to start.

8. Pius XII in 1950: Tomb Found, Bones Uncertain

Pius XII announced the results of the excavation in a radio message at Christmas 1950, and the wording he chose is a model of how to make a claim without overstating it. He said that the tomb of the Prince of the Apostles had been found. On the human remains recovered, he said that it was not possible to prove with certainty that they belonged to the body of the apostle, and he added that this left the essential fact of the tomb itself untouched.

The two statements paraphrased above are from the Christmas radio message of Pope Pius XII of 1950, published by the Holy See, and from the official excavation report of 1951. Readers who want the exact wording should consult those sources directly rather than this summary.

That is the shape of the honest claim. The place is established. The bones are not. A pope with every incentive to announce a relic declined to do so, in public, at Christmas, in front of the world, because the archaeologists working for him could not support it.

What Had Been Found Under the Shrine

Bones had been recovered from the earth beneath the aedicula. When they were examined they turned out to represent more than one individual, and animal bones were mixed in with them, which is what happens to a grave in fill that has been dug through repeatedly for sixteen centuries. Nothing about that assemblage could be assigned to a single named person. Pius XII's caution followed directly from it.

9. Guarducci and the Bones from Wall g

Margherita Guarducci was a Greek epigrapher at the University of Rome, and she came to the site in the 1950s to study the graffiti on Wall g. Working through the record of the dig, she came to believe that the excavation had lost track of the material taken from the marble-lined cavity inside that wall in 1942, and she went looking for it. She located a wooden box of bones in a storeroom, traced its contents back to the loculus through the testimony of the workman who had helped Monsignor Kaas remove them, and had them examined scientifically.

What the Anthropologist Reported

The anthropologist Venerando Correnti examined the material. His report described bones belonging to a single individual, a male of robust build, aged somewhere in the range of sixty to seventy at death, with parts of most regions of the skeleton present and the bones of the feet absent. Earth adhered to the bones, and fragments of a textile, purple with gold thread, were found with them. Guarducci argued that the earth matched the soil of the grave under the aedicula, that the purple and gold cloth indicated an honourable re-deposition, and that the missing feet were consistent with a body cut down from a cross.

The anthropological findings summarised here are those published by Venerando Correnti in connection with Margherita Guarducci's study of the relics, principally her 1965 volume on the relics of Peter beneath the Vatican confessio. The objections summarised in section 11 were published by Antonio Ferrua and other specialists. This page reports both bodies of published work and settles neither.

The Reconstruction She Proposed

Guarducci's account runs like this. Peter was buried in the plot in the 60s. A memorial was raised over the grave about a century later. Around 250, when Wall g was built and the Red Wall was cracking, the remains were lifted from the disturbed ground and re-deposited in the marble-lined cavity inside the new wall, wrapped in a costly cloth, at the very point where the graffiti cluster. There they stayed until 1942, when they were removed without proper record, and until 1953, when she found them again.

Whether that reconstruction is right turns on one link: the chain of custody between the cavity in 1942 and the box in the storeroom in the 1950s. Everything downstream of that link is careful science. The link itself rests on recollection rather than on excavation records, because the excavation records for that removal were not made.

10. What Paul VI Actually Said in 1968

On 26 June 1968, at a general audience, Pope Paul VI announced that relics of the apostle Peter had been identified. His wording was that the investigations had been carried out with great care and had reached, in a manner he considered convincing, the conclusion that the relics of the apostle had been found. The bones were afterwards placed in transparent containers and returned to the cavity in Wall g, beside the aedicula, where they remain.

The 1968 statement summarised here is the address of Pope Paul VI at the general audience of 26 June 1968, published by the Holy See. Readers should consult the published text for the exact wording, which is more carefully hedged than most retellings suggest.

What Kind of Statement That Is

Reading a papal statement correctly means knowing what sort of act it is. This one was a report of a finding, given at a general audience, in language expressing the pope's own judgement of persuasiveness. It defined nothing. Nothing in Catholic teaching turns on it. A pope cannot make a disputed piece of archaeology certain, and Paul VI did not claim to. He said the results struck him as convincing, which is a description of his conviction about the evidence.

The relics have since been treated as relics. On 24 November 2013, at the closing Mass of the Year of Faith, Pope Francis had the bronze reliquary containing the fragments brought out and displayed publicly in St Peter's Square. In 2019 Francis gave a reliquary of bone fragments venerated as the apostle's to Ecumenical Patriarch Bartholomew I of Constantinople, a gesture the Ecumenical Patriarchate spoke of publicly at the time, and one aimed at the wound between Rome and Constantinople that the guide to the Great Schism of 1054 takes up.

11. What Remains Disputed

Four specific points are argued over by people who know the site well, and a reader who wants to be accurate should be able to name them.

The 1942 Removal

The bones from the loculus were taken out without the stratigraphic recording that governed the rest of the excavation, and stored. Antonio Ferrua, one of the original excavators, and others after him have argued that material handled this way cannot afterwards be tied securely to its find spot, and that a reconstruction assembled a decade later from memory is a weak foundation for an identification. This objection is procedural and it is serious. It does not accuse anyone of dishonesty. It says that the record needed to support the claim was never made.

The Reading of the Inscription

The Petros eni fragment is broken, short, and read differently by different epigraphers, including by the man who first published it. Guarducci's wider theory of cryptographic graffiti has not been generally adopted. Where a scholar's method is contested, the conclusions built with that method inherit the contest.

The Anthropological Inferences

Correnti's description of a robust male of about sixty to seventy is a legitimate finding from the bones. The steps taken from there to Peter are inferences. An elderly, well-built man in a Roman cemetery is not a rare thing. The absent foot bones are consistent with crucifixion and consistent with many other explanations, including simple loss during two thousand years of disturbance, and the argument from missing feet is the weakest link that popular accounts lean on the hardest.

The Absence of Independent Testing

No radiocarbon dating or genetic analysis of these bones has been published. Until such work is published and reviewed, the identification rests where Guarducci left it. Whether such testing should be done is a real question, weighing the reverence owed to relics against the value of information, and reasonable Catholics differ on it. The comparison worth making is with the Turin shroud, where published testing produced results that are themselves fiercely argued over, a case the guide to the Shroud of Turin sets out.

None of these four objections touches the site. They touch the bones. A reader can accept every one of them and still hold, on the evidence of the aedicula, the graffiti, Gaius and Constantine's earthworks, that the Roman church has been venerating this spot as Peter's grave since living memory of the apostle.

12. The Rival Burial Claims

Two alternative locations come up often enough to need answering, and neither has the standing of the Vatican site.

San Sebastiano on the Appian Way

Under the basilica of San Sebastiano, south of Rome on the Via Appia, excavators found a third-century covered courtyard, called the triclia, whose walls carry scores of scratched invocations of Peter and Paul left by people who ate funeral meals there. The graffiti are dated to around the middle of the third century, and they show beyond doubt that this was a cult site of both apostles at that date. One old explanation was that the bodies had been moved here for safekeeping during the persecution under Valerian in 258 and later taken back. Later scholarship has generally moved away from a translation of the bodies and toward reading the site as a memorial and meal place established for the two apostles, in a city where their actual graves lay elsewhere. The Roman calendar's ancient entry for 29 June, listing Peter on the Vatican and Paul on the Ostian Way, points the same way.

The Jerusalem Ossuary

A bone box from the Franciscan excavation at Dominus Flevit on the Mount of Olives has been promoted in popular literature as bearing the name Simon bar Jonah and containing the apostle. The reading of the inscription is contested, Simon was among the commonest names in first-century Judaea, the ossuary sits in a cemetery of ordinary Jewish burials, and the excavators themselves made no such claim. Historians of the period, Catholic and otherwise, have not taken the identification up.

13. What the Church Asks You to Believe

Catholic faith does not rest on the identification of any relic, and it does not rest on this one. The articles of the Creed concern God, Christ, the Spirit, the Church, forgiveness, resurrection and eternal life. The authenticity of a bone is a question of historical fact, open to evidence and to revision, and no Catholic is required to hold a position on it.

The veneration of relics is a practice of popular piety that the Church commends and regulates. The Catechism treats such devotions among the forms of piety that surround the sacramental life of the Church and calls for them to be guided by pastoral discernment (CCC 1674 to 1676). The Council of Trent, in its decree of 1563 on the invocation and veneration of the saints, taught that the bodies of the martyrs are to be venerated by the faithful, and in the same breath required bishops to prevent abuses and to permit no new relics without proper examination. Caution about relics is an old Catholic instinct and a Catholic obligation.

Why the Grave Still Matters

Relics matter for a reason that runs deeper than curiosity. Christianity claims that God entered a body, that a particular man died on a particular afternoon under a named governor, and that bodies will rise. A faith with those claims cannot be indifferent to graves. Honouring the bones of the martyrs is a statement that the dead in Christ are persons awaiting resurrection, and that their bodies are part of who they are. The guide to the resurrection of the body sets out what the Church holds about that.

The Vatican grave says something more particular. The man honoured under that altar denied Christ three times in a courtyard because he was frightened of a servant girl, and Scripture keeps the story in, in all four Gospels, without softening it.

The Church that raised St Peter's over that grave was making a claim about grace. The rock was a coward who was restored, sent, and who ended by dying where he had once run away. The altar stands over the failure as well as the martyrdom. That is what pilgrims are looking at through the grille of the confessio, and knowing what is actually down there, with its arguments and its uncertainties intact, makes the looking more honest rather than less.

14. Scavi, Grottoes and Confessio

Three different levels under St Peter's get confused with one another, and telling them apart saves a wasted visit. From the top down they are the confessio, the grottoes and the Scavi.

The Confessio

The confessio is the sunken semicircular well in front of the papal altar in the basilica itself, ringed with oil lamps, with a double stair curving down into it. Anyone inside the church can walk up to its rail and look down. At the bottom is the niche of the pallia. The floor at that level is the floor of Constantine's basilica, and the shrine lies below it. That is as close as most visitors get, and it is close.

The Grottoes

The Vatican Grottoes are the low vaulted space under the present basilica floor, at roughly the level of the old Constantinian church, containing the tombs of many popes. Access is from within the basilica and is ordinarily open to visitors without any special arrangement. The Clementine Chapel there stands immediately behind the shrine, which is the nearest point of open public access to the tomb.

The Scavi

The excavations themselves are a different matter. The necropolis lies below the grottoes, reached by a controlled route, and it is not part of the ordinary visit to the basilica. Numbers are kept low, groups are small and led, and access is managed by the Excavations Office of the Fabbrica di San Pietro rather than by any tour company. Conditions underground are warm and humid, the passages are narrow, and the site is unsuitable for anyone who cannot manage confined spaces and steps.

Arrangements, conditions of entry and available dates change, and this page gives no figures for them. Anyone who wants to go should write to the Excavations Office directly and well ahead, and should treat any third party promising immediate access with suspicion. For planning a wider Roman visit around the major basilicas, see the guide to pilgrimage sites in Rome, and for what the Church means by going to a place at all, the guide to what a pilgrimage is.

15. Frequently Asked Questions