Sometimes non-Catholic Christians question whether St Peter was ever in Rome. The New Testament itself offers pretty slim evidence. All we have is the verse at the end of the first epistle of Peter which says he is in Babylon with Mark. (1 Pt. 5:13)
However, when the rest of the documentary evidence is compliled we find that Papias (108) confirms Mark’s presence with Peter, saying that Mark’s gospel was based on the memories and sermons of Peter. Clement of Alexandria repeats the tradition that Mark wrote his Gospel in Rome at the request of the Christians there, who asked for a written memorial of Peter’s preaching. This is also recorded in Eusebius.