Pope - The Pope (from Latin: papa, Papa, father; from Greek: pappas/ p?ppa?, father)[1] is the Bishop of Rome and the spiritual leader of the Roman Catholic Church. He is believed by Catholics to fulfill this role as the Successor of Saint Peter, making him Vicar of Christ. The office of the Pope is called the Papacy; his ecclesiastical jurisdiction is called the Holy See (Sancta Sedes in Latin) or Apostolic See (this latter, on the basis that both St. Peter and St. Paul were martyred at Rome). Early bishops occupying the See of Rome were designated Vicar of Peter; for later Popes the more authoritative Vicar of Christ was substituted; this designation was first used by the Roman Synod of 495 to refer to Pope Gelasius I, an advocate of papal supremacy among the patriarchs. Marcellinus (d. 304) is the first Bishop of Rome whom sources show used the title of Pope. The current Pope is Benedict XVI. In addition to his service in this spiritual role, the Pope is also Head of State of the independent sovereign State of the Vatican City, a city-state and nation entirely enclaved by the city of Rome. Before 1870 the Pope's temporal authority extended over a large area of central Italy: the territory of the Papal States. The Papacy retained sovereign authority over the Papal States until the Italian unification of 1870; a final political settlement with the Italian government was not reached until the Lateran Treaty of 1929.