The Diocese of Rome (Latin: Dioecesis Urbis seu Romana; Italian: Diocesi di Roma) 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 it has civil jurisdiction over Vatican City (located geographically within the city of Rome). The Diocese of Rome consists of two geographical jurisdictions: the Vicariate of Rome, and the small Vicariate of Vatican City. It is the metropolitan diocese of the Province of Rome, an ecclesiastical province in the Ecclesiastical Region of Lazio in Italy. According to Catholic tradition, the first bishop of Rome was Saint Peter during the first century.
Historically, many Rome-born men – as well as others born elsewhere on the Italian peninsula – served as bishops of Rome. Since 1900, however, there has been only one Rome-born bishop of Rome, Pius XII (1939–1958). In addition, throughout history, non-Italians have served as bishops of Rome, beginning with the first of them according to Catholic tradition – Saint Peter.