Catacombe di San Pancrazio under the basilica in Trastevere, Rome

Beneath the cypress and pine trees along the Appian Way and other roads leading out of ancient Rome extends a vast city of the dead.  Here, in the first centuries AD, early Christians carved out labyrinths of dark tunnels, some on three or four levels, to host underground tombs and secret chapels.

Excavated tombs in the Catacombs of Domitilla and Priscilla confirm a progressive Christianization of earlier pagan cemeteries.  In these subterranean tunnels pilgrims can become eyewitnesses to the emergence of Christianity as part of Roman society.


Another road leading out of Rome, the Via Ardeatina, was lined with tombs and mausoleums slightly less imposing than those of the nearby Appian Way.  Here the first-century patrician Roman matron, Flavia Domitilla, wife (or niece, according to some historians) of the martyred Christian Consul Flavius Clemens and niece of the Emperor Domitian (81-96), granted some of her personal property to her freed slaves for Christian burials.  Four first-century inscriptions found on the property give evidence of Domitilla’s ownership of the estate and of her generous donation.

In 96AD, the Emperor Domitian exiled the openly Christian Domitilla (historians of the time reported she had been accused of ‘Jewish practices’) to the island of Ponza, where she died a slow, lonely death – she is thus sometimes considered a martyr.

Scholars tell us that around 100AD the small cemeteries, located at some distance from one another on Domitilla’s property, sprouted underground galleries on several levels and developed, during the next three centuries, into the vast Catacomb of Domitilla.  The Catacomb of Priscilla had a similar beginning.

One of early Christianity’s greatest strengths was its appeal to all classes of Roman society.  The downtrodden, slaves and soldiers, but also prosperous aristocrats, accepted the Christian message of redemption through Christ.  The legal position of married Roman women, who could own and dispose of property in their own right, was a great boon for early Christianity.


Most catacombs were founded because of the generosity of wealthy Roman converts.  Their amazing expansion was usually due to the presence of beloved saints and martyrs among the buried dead.  Between the end of the third century and the beginning of the fourth, the bodies of two martyrs, Nereus and Achilleus, were placed in a crypt in the third level of Domitilla’s cemetery.  According to tradition, these two soldiers of the Praetorian Guard of Diocletian (284-305), accustomed to executing Christians, were themselves converted, martyred by decapitation, and buried in Domitilla’s Catacomb.

Soon an intense cult developed in their honour and graves mushroomed around their tombs.  Pope Damasus built an underground basilica on the site, which was enlarged by Pope Siricius (384-99).  Today, in the reconstructed basilica, we can see an apparently very early sculpture of Achilleus’ decapitation; it graces a column which originally supported Damasus’ altar, but now stands alone among sarcophagus fragments.

Another moving illustration of retro sanctus (behind the saints) burials may be seen in a crypt behind the basilica apse.  Here, a vivid fourth-century wall fresco shows the deceased Veneranda being introduced into paradise by St. Petronilla, whose tomb must have been located nearby.  This Petronilla has caused much controversy and debate.  Was she merely a pious woman, and not a saint at all, as some claim?  Or was she, as popular legend holds, St. Peter’s daughter?

A tradition dating from a second-century copy of the apocryphal Acts of Peter relates that the Apostle had a paralysed daughter.  Entreated by the crowds, St. Peter healed the girl, but only temporarily; her let her walk around for a bit, then restored her paralysis as beneficial for her soul.  We have sixth-century accounts of pilgrims visiting the Domitilla Catacomb to venerate the grave of Petronilla, Peter’s daughter.  They describe her sarcophagus, with her name and the inscription ‘dearest daughter’.

In 757 Petronilla’s remains were solemnly transported to St. Peter’s Basilica and placed in a rotunda next to the left transept.  A twin rotunda on the right transept was dedicated to Peter’s brother, St. Andrew, so there seems to have been some family connection.  Somehow Petronilla was adopted as the patroness of the Franks, and her mausoleum eventually became the French monarchy’s official chapel in Rome (for which Michelangelo’s Pieta was commissioned by a French ambassador).  Today’s visitor to St. Peter’s will not find Petronilla’s shrine, however.  In the splendid new Renaissance-Baroque structure, her rotunda disappeared without a trace; her sarcophagus was placed upside down on the floor of the Blessed Sacrament chapel.  Petronilla now has her own small altar, to the right of the Papal Throne (and Clement X’s memorial).


Excerpt from Hager, June. Pilgrimage: A Chronicle of Christianity Through the Churches of Rome.  (Weidenfeld & Nicolson: London), 1999.

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