Three hundred thousand people visit St. Peter’s Square every day. Most of them photograph the basilica. Some notice the obelisk. Almost none read the inscription on its base.
It says: Christus vincit, Christus regnat, Christus imperat. Christ conquers, Christ reigns, Christ commands.
On the other side: Ecce Crux Domini, fugite partes adversae. Behold the Cross of the Lord, flee hostile powers.
These are exorcism prayers. They were carved into the pedestal in 1586, after Pope Sixtus V had the obelisk doused with holy water and crowned with a cross. The stone needed cleansing. It had spent fifteen centuries in bad company.
Beneath the square, beneath the basilica, beneath the grottoes where popes are buried, there is another city. It belongs to the pagan dead.
The Sun Stone
The obelisk standing at the center of St. Peter’s Square today is Egyptian, a column of red granite over 25 meters tall, weighing 326 tonnes. It was quarried for Heliopolis, the City of the Sun, and carved for an unknown pharaoh at an unknown date. It carries no hieroglyphs, and nobody knows why: either it was made blank, or someone erased the inscriptions before it left Egypt. Augustus moved it to Alexandria’s Forum Julii after conquering Egypt, where it stood until Emperor Caligula shipped it to Rome.
Caligula brought it across the Mediterranean around 40 AD. He placed it on the spina, the central spine, of his private circus on Vatican Hill. The circus sat in the Horti Agrippinae, gardens he inherited from his mother Agrippina the Elder. Claudius finished the construction, and Nero opened the circus to the public.
In July 64 AD, Rome burned. Nero blamed the Christians. Tacitus, writing fifty years later, described what happened next in the Vatican circus: executions by the hundreds, some dressed in animal skins and torn apart by dogs, others set on fire to serve as human torches lighting the night races. The obelisk stood at the center of the track. It watched.
According to the earliest traditions, the apostle Peter was among those killed here. Clement of Rome, writing around 96 AD, says Peter “through unjust envy endured many labours, and at last, having delivered his testimony, departed unto the place of glory due to him.” Clement does not say where, or how. A century later, a Roman presbyter named Gaius was more specific. “If you will go to the Vatican,” he told a rival theologian, “you will find the trophies of those who laid the foundations of this church.” Eusebius preserved this quote in his Ecclesiastical History (Book II, Chapter 25). The word “trophy” (tropaion) meant a memorial erected at the site of a martyr’s death. By 200 AD, Christians knew exactly where on Vatican Hill Peter had fallen.
The circus was abandoned by the mid-2nd century. Some scholars think the memory of what happened there drove people away. The obelisk remained. It stood through the cemetery that grew around it, through Constantine’s basilica, through twelve centuries of pilgrimage, through the demolition of Old St. Peter’s and the construction of the new one, and it never fell.
In 1585, Pope Sixtus V decided to move the obelisk, wanting it centered in front of the new basilica. He convened a council, and nearly 500 engineers submitted proposals. Domenico Fontana won the commission by building a working scale model in lead.
The operation took thirteen months of preparation. On the day of the first lift, Sixtus V decreed silence in the square on penalty of death. Eight hundred men and 160 horses worked 45 winches, with trumpet blasts signaling the numbered capstans to pull and a bell on the scaffold signaling everyone to stop. The obelisk rose.
A later story, appearing about two hundred years after the event, says a sailor in the crowd saw the ropes overheating and shouted “Acqua alle funi!” (“Water on the ropes!”), saving the operation. Fontana published a detailed book about the project in 1590. The sailor does not appear in it. The story is a good one, but it is probably fiction.
On September 10, 1586, the obelisk rose into its new position. Eighteen days later, the scaffolding came down. The bronze ball that had crowned the obelisk for fifteen centuries, believed throughout the Middle Ages to contain the ashes of Julius Caesar, was removed and opened. It was empty. Sixtus V gave it to the city, and it sits in the Capitoline Museums today.
The pope replaced the ball with a gilt crucifix, said to contain a fragment of the True Cross. He performed the rite of exorcism over the stone and had the prayers carved into the base. An Egyptian sun monument, older than Rome itself, now bore the words: Christ conquers.
The bronze ball that crowned the Vatican obelisk for fifteen centuries was believed to hold Caesar’s ashes. When it was opened in 1586, it was empty.
The Circus and the Martyrs
The Circus of Caligula covered an area of roughly 350 by 90 meters. Its southern perimeter was confirmed by excavations in the 1940s and 1950s, when archaeologists found curved walls beneath the Vatican grounds. The Via Cornelia ran along its northern edge, lined with tombs.
This was where Peter died. That much is as close to certain as ancient history allows. Clement of Rome wrote within living memory of the event. Gaius placed the memorial at the Vatican within 130 years. The apocryphal Acts of Peter, composed in the late 2nd century, added the detail that Peter was crucified upside down, requesting the inversion because he considered himself unworthy of dying in the same manner as Christ. The story is famous. The source is weaker than the others. Clement, Ignatius, Irenaeus, Tertullian, and Eusebius all attest to Peter’s death in Rome. Only the Acts of Peter specifies the position.
After the persecutions, the circus fell out of use. By 150 AD, the area had become a cemetery. Families built mausolea along the Via Cornelia and across the abandoned grounds. The dead moved in where the racers had competed and the martyrs had burned. By the time Constantine arrived in the early 4th century, Vatican Hill was a city of tombs.
Twelve Meters Down
In 1939, workers preparing a tomb for Pope Pius XI in the Vatican Grottoes, the space between the old floor level and the new basilica above, broke through a wall. Behind it, a brick structure descended deep into the earth. They had found a Roman mausoleum.
Pope Pius XII authorized a full archaeological excavation. While the Second World War consumed Europe, a team of archaeologists dug beneath St. Peter’s in near-total secrecy. The work continued from 1940 to 1949. What they uncovered was an entire Roman cemetery: 22 mausolea arranged along a funerary road, containing more than a thousand burials, at depths between 5 and 12 meters below the basilica floor.
This was an open-air cemetery. These were above-ground tombs with doors, windows, frescoed walls, and mosaic floors. Wealthy Roman families had buried their dead here from the 1st century through the early 4th century. The northern row of mausolea dates to the 2nd century, the southern to the 3rd. The last known burial, dated by a coin found in a cremation urn, is from around 318 AD.
The dead are pagan.
Tomb Z: The Egyptians
The tomb they call the Tomb of the Egyptians takes its name from a painting of Horus, the Egyptian god of the dead, on the center of its north wall. Six sarcophagi fill the space, along with four arcosolia, arched burial niches cut into the walls. The most elaborate sarcophagus shows a Dionysian bacchanal: Dionysus in a chariot driven by a centaur, surrounded by fauns, bacchants, and corybants, while Ariadne sleeps in the depths of a forest. The lid of another sarcophagus depicts an aerial dance of maenads.
Horus at the door. Dionysus on the coffin. Roman dead in an Egyptian-guarded, Greek-decorated tomb, twelve meters below the pope’s altar.
Tomb I: The Chariot
A black-and-white mosaic covers the floor: Pluto abducting Persephone, god of the underworld seizing the daughter of the harvest goddess, driving his chariot while Mercury leads the way. Tigers and gazelles line the border, interspersed with vases and flowering plants. The walls show country scenes with peacocks, doves, and ducks among the flowers.
The Romans chose this story for a tomb. A young woman dragged into the land of the dead. It was a comfort image: even the gods go underground. Even they come back.
The Mausoleum of the Valerii
This 2nd-century tomb survived Constantine’s construction almost intact. When his engineers packed the surrounding mausolea with rubble, the Valerii tomb was sealed with its frescoes and stucco work preserved. The walls are painted to imitate polychrome marble. The white stucco decorations are modeled to look like marble statues, including family portraits. Vatican archaeologists call them “of extraordinary value.”
The Valerii family paid for fake marble made of plaster, and it lasted 1,800 years because an emperor buried it in earth. Their real marble-owning neighbors were less lucky. Most of those tombs were gutted to make room for fill.
Mausoleum M: The Sun God, or the Son of God
This is the tomb that matters most.
Built for a man named Julius Tarpeianus and his family in the late 2nd or early 3rd century, Mausoleum M contains a vault mosaic that has generated more scholarly argument than any other image in the necropolis. It shows a male figure wearing a radial crown, riding a quadriga (a four-horse chariot, though only two horses survive). He holds a blue globe in his left hand. He wears a tunic and a windswept cloak. Rays extend in all directions against a gold background. Twisting green vines frame the scene.
The figure looks like Sol Invictus, the Unconquered Sun, the solar deity that Roman emperors increasingly promoted from the 3rd century onward. But the other images in the tomb tell a different story. The north wall shows a fisherman. The west wall shows a shepherd carrying a lamb on his shoulders. The east wall shows a sea creature swallowing a human figure. A fisherman (Matthew 4:19), the Good Shepherd (John 10:11), Jonah and the whale. These are Christian images.
Most scholars read the mosaic as Christ depicted in the visual language of Sol Invictus. Christus-Sol. The sun god’s chariot carrying the Son of God. It is one of the earliest known monumental depictions of Christ, dated to around the mid-3rd century. The art historian Steven Hijmans disagrees. He argues the entire tomb is pagan, the surrounding imagery representing a mythological cosmos across sea, land, and sky, with no Christian content at all.
Both readings are defensible. The mosaic sits at exactly the historical moment when the boundary between the sun god and the Son of God had not yet been drawn. Constantine himself kept Sol Invictus on his coins until 323 AD, more than a decade after his conversion. He was baptized only on his deathbed in 337. The Julii tomb mosaic is a physical artifact of a time when a Roman family could put Christ’s stories on their walls and the sun god’s crown on his head, and see no contradiction.
When Constantine sealed the Vatican cemetery in the 4th century, some families were still actively burying their dead. A coin in one cremation urn dates to 318 AD.
Peter Is Here. Or Peter Is Not Here.
The excavators were not digging for pagan art. They were looking for Peter.
In 200 AD, the presbyter Gaius had told his opponent to go to the Vatican and see the “trophy” of the apostle. In the 1940s, the archaeologists found it. Beneath the high altar of St. Peter’s Basilica, directly below the spot where popes have celebrated Mass for seventeen centuries, they uncovered a small funerary shrine: two niches, one above the other, set against a red stuccoed wall. The “Red Wall.” The structure dates to approximately 150-167 AD, built during the pontificate of Pope Anicetus.
This is the Trophy of Gaius. A 2nd-century memorial marking the spot where the earliest Christians believed Peter was buried. It was built roughly 80 to 100 years after Peter’s death.
Against the Trophy, someone built a perpendicular wall around 250-260 AD. Wall G, the Graffiti Wall. It is covered with scratched inscriptions in Latin, charcoal marks, and stylus scratches. Names, prayers, invocations of Christ and Peter. Pilgrims had been coming to this wall for at least sixty years before Constantine broke ground.
In the wall, archaeologists found a small cavity, a loculus, containing skeletal remains placed in a marble container. A forensic analysis in 1963 identified the bones as belonging to one male, aged 60 to 70, of heavy build. The bones were wrapped in purple wool fabric interwoven with gold thread.
Margherita Guarducci, an archaeologist and epigraphist, spent years deciphering the graffiti on Wall G. She identified approximately twenty symbols as coded Christian messages from the era of persecution. Her most significant reading was an inscription on the Red Wall: PETROS ENI. Peter is here.
Pope Paul VI announced in 1968 that the bones of the apostle had been identified. Pope Francis, after a review initiated by Benedict XVI, reaffirmed this conclusion in 2013.
Antonio Ferrua, the archaeologist who had preceded Guarducci on the excavation, disputed her reading for the rest of his life. The inscription is damaged and the letters incomplete. PETROS ENDEI, Peter is not here, is an equally plausible reading of the surviving marks. Ferrua, from his position as rector of the Pontifical Institute for Christian Archaeology, marginalized Guarducci and challenged her methodology.
Pius XII himself, the pope who authorized the excavation, was cautious. He said it was “impossible to prove with certainty that they belong to the body of the apostle.”
The evidence is real. The Trophy is real. The pilgrim graffiti is real. The bones of a 60-to-70-year-old man wrapped in imperial purple are real. Whether these are Peter’s bones depends on four damaged letters scratched into a wall, and on which archaeologist you trust.
Constantine’s Gamble
Here is the question that matters: why did Constantine build here?
He already had a church in Rome. The Lateran Basilica, his first Christian building, was constructed around 312-318 AD on flat, imperial-owned land where he simply demolished military barracks. Zero earthmoving. Zero legal complications. If he wanted a grand church dedicated to Peter, he could have built it there.
Instead, he went to Vatican Hill.
His engineers cut into the northern slope and built up the southern side with fill, constructing six great retaining walls running the length of the building and moving more than 40,000 cubic meters of earth. The depth to stable soil varied from 15 meters on the north side to 25 meters on the south.
The cemetery was still active. A coin in one cremation urn dates to 318 AD. Families were still burying their dead when the construction crews arrived. Roman law classified burial sites as loca religiosa, sacred and inviolable. The ius sepulchri protected the graves. Constantine overrode this with imperial authority, but he used a compromise: the dead stayed where they were. His engineers removed the roofs of the mausolea, left the walls standing, and packed the interiors with rubble and earth, creating a honeycomb foundation. Some tombs on the steeper western slope were sealed with their roofs intact. The Valerii mausoleum survived with its frescoes untouched.
He centered the entire basilica on the Trophy of Gaius. One small 2nd-century shrine, a simple pair of niches in a red wall, dictated the position of the largest church in the Christian world. He encased the Trophy in marble and placed the altar directly above it.
The traditional explanation is straightforward: Peter was buried here, and 150 years of continuous Christian pilgrimage made the location unmovable. The Trophy, the graffiti, the pilgrim traffic, all of this had made the Vatican the only possible site for Peter’s church.
The skeptical reading (advanced by scholars like Bart Ehrman) says the tradition could be wrong. The Trophy could mark a symbolic memorial. The bones could belong to anyone.
Both readings arrive at the same conclusion. Something at that exact spot, whether Peter’s actual remains or an unbroken chain of belief stretching back to within a generation of the apostle, was powerful enough to make an emperor move a mountain. Constantine spent more money, violated more laws, and solved more engineering problems to build on Vatican Hill than on any other construction project of his reign.
Constantine’s relationship with Christianity was complicated. He kept Sol Invictus on his coins for a decade after Nicaea. He postponed his baptism until his deathbed. The Christ-Sol mosaic in Mausoleum M, the image of Christ wearing the sun god’s crown, may be the most honest portrait of the religious world Constantine actually inhabited: one where the sun and the Son had not yet separated.
He buried that mosaic under his basilica. He built the floor of his church over the face of the sun god. Whether he knew what he was covering is impossible to say.
The Great Mother’s Blood
While Constantine’s basilica rose on one side of Vatican Hill, the Great Mother’s priests were still working on the other.
The cult of Cybele, the Magna Mater, arrived in Rome in 204 BC during the Second Punic War. Hannibal was in Italy. The Senate was desperate. They consulted the Sibylline Books, the ancient collection of oracular prophecy, and received an answer: bring the Great Mother from Phrygia, and Rome will be saved. A delegation traveled to Pessinus in central Anatolia and returned with Cybele’s most sacred object, a large black meteorite, an aniconic image of the goddess. The stone arrived at Ostia in April 204 BC and was escorted up the Tiber by Publius Cornelius Scipio Nasica, chosen as the most virtuous man in Rome. Rome defeated Hannibal. The cult, like that of many adopted foreign gods, became permanent.
The main temple stood on the Palatine Hill. A second sanctuary, the Phrygianum, was built on Vatican Hill, near the Circus of Caligula, within the imperial gardens. Its exact location is uncertain. The scholar Patrizio Pensabene places it at the site later known as the Rotonda di Sant’Andrea, close to the south entrance of St. Peter’s. The late-4th-century Notitia Regionum Urbis Romae lists it as a recognized cult site in Region XIV.
The archaeological evidence is inscriptional. In 1609, during construction of the new St. Peter’s facade, workers uncovered 24 fragmentary marble altars beneath the foundation. They are cataloged as CIL VI.497-504. All but one had been found under the facade. They date from 305 to 390 AD. Most were dedicated by high-status Romans, senators and aristocrats, commemorating a specific ritual: the taurobolium.
The taurobolium worked like this. A priest descended into a pit while a bull was led onto a wooden platform above him. The bull’s throat was cut. Blood poured down through the slats onto the priest below, drenching him entirely. He emerged reborn.
One inscription contains the phrase in aeternum renatus. Reborn forever.
The parallel with Christian baptism was obvious and was noticed at the time. Both rituals promised new life. One used water. The other used blood. Both were performed on Vatican Hill.
The priests of Cybele were called the galli. They served the goddess through a radical act: self-castration, performed during the Dies sanguinis (“Day of Blood”) on March 24, the day of mourning for Attis, Cybele’s consort who had castrated himself beneath a pine tree. On this day, the galli ran through the streets in ecstasy, flogging themselves until they bled, dancing to pipes and tambourines. In the frenzy, they castrated themselves. Afterward, they dressed exclusively in women’s clothing.
Roman reaction was a mix of revulsion and fascination. The poet Catullus, writing in the 1st century BC, told the story of Attis in his Poem 63. The poem shifts between masculine and feminine pronouns as Attis crosses from one state to the other. Catullus offers sympathy. The Senate was less generous: it passed laws forbidding Roman citizens from becoming galli. Only Phrygian immigrants were allowed to serve. Enough citizens tried to join that the legislation was necessary.
Through the 4th century, two religious communities operated on Vatican Hill side by side. The Phrygianum hosted the galli, the bull sacrifices, the drums and pipes of the Great Mother. St. Peter’s Basilica, with its altar centered above a fisherman’s bones, hosted the Eucharist. Both claimed to offer passage through death. Both occupied the same hill.
The last recorded taurobolium in history took place on May 23, 390 AD. Lucius Ragonius Venustus and Ceionius Rufius Volusianus, members of the Roman aristocracy, performed the sacrifice at the Phrygianum on Vatican Hill. Their altar inscription survives. By then, the taurobolium had become what one scholar called “a hallmark of the pagan nobility in their final struggle against Christianity.”
In February 391, Theodosius, along with co-emperors Gratian and Valentinian II, banned all animal sacrifices. In November 392, a second decree classified offerings to pagan gods as high treason. The Phrygianum fell silent. The altars were buried. Eleven centuries later, in 1609, workers digging the foundations for the new St. Peter’s facade pulled them out of the ground.
The last pagan animal sacrifice recorded in Roman history took place on Vatican Hill on May 23, 390 AD, eighty-five meters from where Peter’s bones lay beneath the altar.
The Hill of Prophecy
Why is it called Vatican?
Aulus Gellius, a Roman writer of the 2nd century AD, gave two answers in his Noctes Atticae (Book 16, Chapter 17). The first: the name comes from vaticinia, prophecies, because a god who inspired divination presided over the field. The second, attributed to Marcus Terentius Varro, Rome’s greatest antiquarian: a minor deity called Vaticanus held dominion over the beginnings of the human voice. When a newborn draws its first breath and cries, that cry, vagitus, belongs to Vaticanus. The first syllable of “Vaticano” is the sound a baby makes.
Augustine knew this. In The City of God (Book 4), he mocked Vaticanus three times while ridiculing the Roman habit of assigning a god to every minor function. Vaticanus, he wrote, “presides over the cries of infants,” one of a mob of gods so specialized they tripped over each other’s jurisdictions.
The hill sat on the Etruscan side of the Tiber. The Romans called the right bank the Ripa Veientana or Ripa Etrusca, the Etruscan shore, marking the old boundary between Rome and the powerful city of Veii. The 19th-century historian Barthold Georg Niebuhr proposed that the name derived from an Etruscan settlement called Vaticum. No trace of such a settlement has ever been found.
A story circulates online that the name comes from an Etruscan goddess called Vatika, a goddess of the underworld who guarded the dead, and that a hallucinogenic weed called vatika grew on the hillside. The claim appears on dozens of websites. It has no primary source. No peer-reviewed scholar has identified “Vatika” as an Etruscan deity. She does not appear in any standard reference on Etruscan religion, which lists the known underworld deities as Catha, Lur, Suri, Thanr, and Calus. The story is modern internet folklore dressed in ancient clothing.
The honest answer: we do not know why it is called Vatican. Gellius gave us two guesses. Varro gave us a god of crying babies. The Etruscans left no explanation. The hill kept its name through the Republic, the Empire, the fall of Rome, the Middle Ages, the Renaissance, and the modern era. Twenty-one centuries of continuous occupation, and the etymology is still uncertain.
A hill of prophecy. A hill of the first cry. A hill of the dead.
What Lies Beneath
You can visit the necropolis today. The Vatican Excavations Office (Ufficio Scavi) runs tours for small groups. You descend beneath the basilica, past the grottoes where modern popes are buried, into the 2nd-century cemetery.
You walk past Horus. Past Dionysus riding a centaur-drawn chariot. Past Persephone being dragged to the underworld. Past the Valerii family’s stucco portraits, preserved in perfect detail because an emperor sealed them in rubble. Past Mausoleum M, where a 3rd-century artist put a radial crown on Christ’s head, or on the sun god’s head, or on both at once.
Then you arrive at the Red Wall. A simple stuccoed surface, painted red, with a small shrine and a scratched, damaged wall beside it. Pilgrims carved their prayers here for sixty years before Constantine covered it in marble. The wall, where it is still legible, records the names of people who came to this spot to be near Peter.
Guarducci read four letters and announced that the apostle was here. Ferrua read the same letters and said he was not. The bones of a heavy man, aged 60 to 70, wrapped in purple and gold, rest nearby. They may belong to a fisherman from Galilee who died in Nero’s circus around 64 AD. They may belong to someone else entirely.
Above you, forty meters of marble, travertine, and gold. Michelangelo’s dome. Bernini’s baldachin. Five hundred years of Renaissance and Baroque engineering. The largest church in the world, built because one emperor believed what four scratched letters on a red wall told him. Or because the weight of 150 years of pilgrimage was heavier than 40,000 cubic meters of earth.
The obelisk stands outside, blank-faced, bearing no pharaoh’s name and an exorcism prayer. It has been here longer than any of them. Egyptian, Roman, Christian. A sun stone at the center of Christendom. The bronze ball on top was supposed to hold Caesar’s ashes. It held nothing. The cross that replaced it was supposed to hold a piece of the True Cross. A later inspection found nothing inside.
The hill keeps its secrets. It always has.
