Question: : Is Saint Petronilla really the daughter of St. Peter?
Answer: Perhaps, but we will probably never know for sure in this life. The question points to some of the difficulties regularly experienced by historians and hagiographers (those who write biographies of saints).
In The Roman Martyrology the Church seems to officially acknowledge Saint Peter's paternity: "St. Petronilla, Virgin [and Martyr], daughter of the blessed apostle Peter, who refused to marry the nobleman Flaccus. Given three days for consideration, she spent them in fasting and prayer. On the third day, having received Christ sacramentally, she gave up her spirit."
But the less official sources are not all so sure. Some place her death in the first century, where it would have to be if she were Peter's daughter, but others date it as late as the third century. Some, noting that her body was found in the catacomb of Flavian Domitilla, suggest that she was a member of the Roman senatorial family of the Flavii. The inscription on her tomb reads "Aure‘ Petronill‘ Fili‘ Dulcissim‘," possibly indicating relationship to an earlier branch of the Flavii, known as the Aurelii. She is not mentioned in fourth century calendars, but this absence may actually place her death in the first century, before the Church began to venerate the martyrs liturgically.1 A fourth century fresco in the cemetery of Domitilla depicts her about to be put to death.2
But there is some evidence that the Martyrology is accurate in naming Petronilla as St. Peter's daughter. Another painting, made around 356, presents Petronilla "receiving a deceased person (named Veneranda) into heaven."3 This strongly suggests that she was venerated as a saint before this time -- and it is interesting to see her performing the duties normally associated with Saint Peter (perhaps, filling in for her father?).
We know from the Synoptic Gospels and from patristic sources that St. Peter was married, so children are not beyond possibility. Clement of Alexandria related that Peter's wife died a martyr on the same day as Peter (i.e. not after an abnormally brief marriage), and that Peter had children who (in contrast to the daughters of Philip) apparently did not marry. A daughter of St. Peter is mentioned but not named in the apocryphal gnostic Acts of St. Peter. Obviously, the name "Petronilla" could be a diminutive of "Peter."
There is also a known connection between Saint Peter and the family of Domitilla; one that just might explain why his daughter was buried in their cemetery. St.Flavia Domitilla (feastday May 12) belonged to a Christian Family that included the martyred Roman Consul, Flavius Clemens, her uncle. Her servants had been baptized by Saint Peter, and she received the veil of consecrated virginity from Peter's successor, Pope St. Clement. She died in exile, a martyr under the Emperor Domitian (81-96). One might conjecture that, while yet alive, Peter's daughter was taken in by Domitilla's family as a testimony to Peter's memory and that of their lost daughter, and that they buried Petronilla in their cemetery when she died.
The Liber Pontificalis describes the translation of the saint's remains from the cemetery to a mausoleum in St. Peter's Basilica by Pope Paul I. It holds that "the carving of the letters [on the sarcophagus] could be identified as being engraved by St. Peter's own hand out of love for his sweetest child." Pope Paul seems to have believed that he had the relics of his predecessor's daughter.
Historians would object that Pope Paul had little more than circumstantial evidence to connect Petronilla with Peter. The might further object that political considerations made the Pope somewhat less than objective in his identification of the martyr. The Lombards and the Byzantines threatened the papal lands, and a powerful military ally was essential. The French royal family had already developed devotion to the saint as St. Peter's daughter. The chapel to which Pope Paul transferred her remains was to become a Roman burial place for French royalty. The Pope went so far as to decorate the new burial location with dolphins, the symbol of the French heirs apparent. But, of course, such objections are also circumstantial.
On the other hand, hagiography develops under the influence not only of popular piety, but under that of Church discipline as well. The imposition of clerical celibacy in the eleventh century made the concept of a papal child an embarrassment to many who pretended celibacy to be of divine origin. For example, in earlier centuries the murder of the wife and daughter of AdrianII (867-872) would have earned them a place on the calendar as martyrs -- but they came along too late in history to be acknowledged. The usually scholarly Catholic Encyclopedia says of the martyrdom only that "He [Pope Adrian] had been married before taking orders, and his old age was saddened by a domestic tragedy."
Saint Petronilla's feast is commemorated on May 31st. All of the hand missals in this writer's possession describe her as a young girl who converted to Christianity under the guidance of Saint Peter; a sort of "God-child." None of them associate her with a Roman family in the third century. One day we will know.
1. Catholic Encyclopedia, s.v. "Petronilla."
2. Katherine Rabenstein, http://users.erols.com/saintpat/ss
3. Catholic Encyclopedia, ibid.
4. Matthew viii: 14-17; Mark i: 29-34; Luke iv: 38-41; St. Melito of Sardis, The Book of the Passing of the Most Holy Virgin, the Mother of God; Eusebius, Ecclesiastical History, Book III, Chapter XXX (quoting St. Clement of Alexandria).
5. Eusebius, ibid.
6. Dom Prosper Guéranger, The Liturgical Year, Vol. VIII (May 12th)
7. Raymond Davis, Trans., The Lives of the Eighth-Century Popes (Liber Pontificalis) (Liverpool: University Press, 1992), p. 81.
8. Catholic Encyclopedia, s.v. "Adrian II."