The Pope (from Latin: papa, tutor; from Greek πάπας (papas); father - originally written πάππας (pappas), as in Homer's Odyssey, book VI, line 57) is the Bishop of Rome, the spiritual leader of the Roman Catholic Church and head of state of Vatican City. Faith communities which recognize Apostolic Succession acknowledge the Bishop of Rome as successor of Saint Peter. As such, Catholics believe the pope to be the Vicar of Christ, while the other faith communities dis-acknowledge Petrine primacy among the bishops. The office of the pope is called the papacy; his ecclesiastical jurisdiction is called the "Holy See" (Sancta Sedes in Latin) or "Apostolic See" (the 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. Pope Marcellinus (d. 304) is the first Bishop of Rome whom sources show used the title of pope. In the 11th century, after the East-West Schism, Pope Gregory VII declared the term "Pope" to be reserved for the Bishop of Rome.