1. The official lists and records of the Roman
Church, some of which must rest upon earlier sources, accept the whole question as proved and recognised generally.
2. The transference of Peter's remains to a new resting place in 258 shows that the tradition was definite and unquestioned early in the third century.
3. The writings of Caius, Origen, Clement of Alexandria, and Tertullian indicate that the theory was accepted in Asia, Alexandria, Carthage, and Rome at the same period.
4. A passage from Irenæus, who probably used the official documents in Rome and who may have known St. John and his companions, carries the legend back to the second century.
5. The testimony of Dionysius of Corinth (d. 165), Papias, and Ignatius (d. 114) carries the belief back through the second to the first century.
6. The clear testimony of Clement of Rome makes a connecting link at the close of the first century.
Hence when the various pieces of evidence—the official sources, the monumental testimony, and the writings of the early Fathers,—which are independent and consistent, are combined they form a solid body of proof, which is practically irresistible, that Peter was in Rome. Likewise the absolute absence of any rival tradition from other cities adds greatly to the probability.
Peter's presence and death in Rome may be admitted as an established fact. If in Rome, whether one year or twenty-five years, Peter, with his aggressive nature, with his marked ability for leadership, and with his capacity for organisation, must have had a great deal to do with the establishment of the Roman Church, either jointly with Paul, or independently of him. Nor
does it seem to be a misuse of the law of historical probabilities to assert that Peter, either with Paul or without him, appointed a bishop for the Church of Rome and transferred to that bishop his apostolic authority. From these facts, based almost entirely upon traditional evidence, coupled with the peculiar primacy conceded to Peter in the New Testament by his fellow Apostles, gradually developed the Petrine theory with all its sweeping claims.