Saint Peter, also known as Peter the Apostle, Simon Peter, Simeon, Simon, or Cephas, was one of the Twelve Apostles of Jesus Christ and one of the first leaders of the early Christian Church. He appears repeatedly and prominently in all four New Testament gospels as well as the Acts of the Apostles. Catholic tradition accredits Peter as the first bishop of Rome‍—‌or pope‍—‌and also as the first bishop of Antioch.

The Diocese of Rome, also called the Vicariate of Rome, is a Latin diocese of the Catholic Church under the direct jurisdiction of the Pope, who is Bishop of Rome and hence the supreme pontiff and head of the worldwide Catholic Church. As the Holy See, the papacy is a sovereign entity with diplomatic relations, and civil jurisdiction over the Vatican City State located geographically within Rome. The Diocese of Rome is the metropolitan diocese of the province of Rome, an ecclesiastical province in Italy. According to Catholic tradition, the first bishop of Rome was Saint Peter in the first century. The incumbent since 13 March 2013 is Pope Francis.