By Giuseppe Monno
According to Christian tradition, the Apostle Peter first came to Rome around A.D. 42, during the early years of the reign of the Emperor Claudius (A.D. 41–54), probably shortly after his miraculous release from prison in Jerusalem (Acts 12:17). This date is suggested by Eusebius of Caesarea in Historia Ecclesiastica (II, 14, 6), although the precise chronology remains a matter of scholarly debate.
In Rome, Peter exercised his apostolic ministry primarily among the Jews of the Diaspora, many of whom were freedmen—former slaves who had been manumitted—living in the capital of the Empire (Historia Ecclesiastica, III, 1). According to Tertullian (De Baptismo, IV, 3), Peter administered baptism in the River Tiber, a place that symbolically stood at the meeting point between the pagan world and the emerging Christian community.
During his stay in Rome, Peter was hosted by Pudens, a Roman senator who had converted to Christianity. Pudens is mentioned by Paul in his Second Letter to Timothy: “Eubulus, Pudens, Linus, Claudia, and all the brethren greet you” (2 Timothy 4:21), a passage that attests to the network of relationships among the Apostles and the early Christian community. According to tradition, in the domus of Pudens—identified with the Titulus Pudentis, today the Basilica of Saint Pudentiana on the Viminal Hill—Peter celebrated the Eucharist together with other members of the young Christian community. These gatherings took place in private homes known as ecclesiae domesticae, the earliest forms of house churches in Rome, as also attested by Hippolytus and the Catalogus Liberianus (fourth century).
After several years, Peter left Rome and traveled to Antioch, the city where, according to the testimony of Paul (Galatians 2:11–14), a well-known disagreement arose between the two Apostles concerning the practice of fellowship between Christians of Jewish and Gentile origin. This controversy was ultimately resolved at the Council of Jerusalem, generally dated to around A.D. 49 (Acts 15:1–35), which established the criteria for admitting the Gentiles into the Christian faith without requiring them to observe the full Mosaic Law.
Peter subsequently continued his missionary activity in other regions of the East. He preached the Gospel in Corinth (1 Corinthians 1:12) and in Pontus, Galatia, Bithynia, and Cappadocia—provinces of Asia Minor mentioned in his First Letter (1 Peter 1:1) and confirmed by Origen (Historia Ecclesiastica, III, 1, 2). During his absence from Rome, the leadership of the Roman Church was entrusted to Linus, one of the earliest collaborators of the Apostles, who is likewise mentioned in 2 Timothy 4:21.
Peter later returned to Rome, where he remained until his martyrdom, which according to tradition occurred in A.D. 67, during the persecution of Christians under the Emperor Nero, following the Great Fire of A.D. 64 (Tacitus, Annales, XV, 44). According to ancient tradition, he was crucified upside down—at his own request, considering himself unworthy to die in the same manner as his Master—in the Circus of Nero, located in the Vatican area. He was buried not far from the place of his martyrdom, in a necropolis along the Via Cornelia, where the Constantinian Basilica of Saint Peter would later be erected (Gaius, cited in Historia Ecclesiastica, II, 25; III, 2; Tertullian, Scorpiace, XV).
Tradition further maintains that Peter served as Bishop of Rome for twenty-five years, from A.D. 42 to A.D. 67 (Jerome, De viris illustribus, 1,1). For this reason he is venerated as the first Pope of the Catholic Church. He was succeeded by Linus, as attested by Irenaeus of Lyons in Adversus haereses (III, 3, 2–3), who provides the earliest known list of the bishops of Rome.
Peter’s preaching in Rome was also decisive for the composition of the Gospel according to Mark. Papias of Hierapolis, a second-century bishop, states that Mark, a disciple and interpreter of Peter, wrote down what Peter had preached orally (cited in Historia Ecclesiastica, III, 39, 15). Clement of Alexandria likewise affirms that the Christians of Rome earnestly requested Mark to set down in writing the memories and teachings of the Apostle (Eusebius, Historia Ecclesiastica, VI, 14, 6). In this way arose the Gospel according to Mark, the first of the Synoptic Gospels, reflecting Peter’s living testimony to the life, death, and Resurrection of Jesus Christ.