Pentarchy

The pope is the bishop of Rome and the head of the worldwide Catholic Church. He is also known as the supreme pontiff, Roman pontiff, or sovereign pontiff. From the 8th century until 1870, the pope was the sovereign or head of state of the Papal States, and since 1929 of the much smaller Vatican City State. From a Catholic viewpoint, the primacy of the bishop of Rome is largely derived from his role as the apostolic successor to Saint Peter, to whom primacy was conferred by Jesus, who gave Peter the Keys of Heaven and the powers of "binding and loosing", naming him as the "rock" upon which the

highest position in the Eastern Orthodox Church

traditional title held by the bishop of Antioch

thumb|400px|Map of the four Eastern Churches in the Pentarchy, c. 500 AD. In this version, almost all of modern Greece, such as the Balkans and [[Crete, is under the jurisdiction of the Holy See of Rome. Emperor Leo III moved the border of the Patriarchate of Constantinople westward and northward, in the 8th century.]]

Archbishop of Alexandria, Egypt; includes the designation "pope"

primate of the Eastern Orthodox Church in Jerusalem