90 The Bishop of Rome is the Bishop of the Church which preserves the mark of the martyrdom of Peter and of Paul: "By a mysterious design of Providence it is at Rome that [Peter] concludes his journey in following Jesus, and it is at Rome that he gives his greatest proof of love and fidelity. Likewise Paul, the Apostle of the Gentiles, gives his supreme witness at Rome. In this way the Church of Rome became the Church of Peter and of Paul". In the New Testament, the person of Peter has an eminent place. In the first part of the Acts of the Apostles, he appears as the leader and spokesman of the Apostolic College described as "Peter ... and the Eleven" (2:14; cf. 2:37, 5:29). The place assigned to Peter is based on the words of Christ himself, as they are recorded in the Gospel traditions.
Source: Ut Unum Sint (Vatican.va)