1 Peter hints that Peter was in Rome, assuming that Babylon symbolizes Rome (1 Pt 5:13). Clement of Rome’s letter does not directly identify the place or the manner of the death of the apostles but adds further weight to the early tradition which associates the martyrdom of Peter and Paul with Rome and with Nero’s persecution. The Church historian Eusebius of Caesaria writes that Peter and Paul had both taught in Rome and then died under Nero. Peter was crucified head down.
The tradition that Peter and Paul were both martyred in Rome gave prestige and authority to the Roman church. Christian churches were proud of their patron saint or martyr. The two founders—Peter and Paul—made the Roman church superior to those who had only one. Moreover, the possession of both martyrs’ shrine provided the Roman church with the presence of the divine and gave the bishop of Rome control over access to the saints. In the fourth century, pilgrimages to the Vatican shrine on the Feast of Sts. Peter and Paul were celebrated with magnificence.