Episcopal polity is a form of church governance which is hierarchical in structure with the chief authority over a local Christian church resting in a bishop . This episcopal structure is found most often in the various churches of Roman Catholic, Eastern Orthodox and other Eastern Church, and Anglican lineage. Some churches founded independently of these lineages also employ this form of church governance.
The pope is the Bishop of Rome and, as such, is leader of the worldwide Catholic Church. The current office-holder is Pope Benedict XVI, who was elected in papal conclave on 19 April 2005. The office of the pope is called the Papacy, and his ecclesiastical jurisdiction the "Holy See" (Sancta Sedes in Latin) or "Apostolic See". The pope is also head of state of Vatican City, a sovereign city-state entirely enclaved by the city of Rome.
The Papal State(s), State(s) of the Church or Pontifical States were one of the major historical states of Italy from roughly the 6th century until the Italian peninsula was unified in 1861 by the Kingdom of Piedmont-Sardinia (after which the Papal States, in less territorially extensive form, continued to exist until 1870).
The list of Popes chronologically lists the men who have been given the title Pope (or Bishop of Rome) by the Catholic Church. While there is actually no official list of popes, the Annuario Pontificio, published every year by the Vatican, contains a list that is generally considered to be the most authoritative. The Annuario Pontificio lists Benedict XVI as the 265th Bishop of Rome.
While the term "Pope" is used in several churches to denote their high spiritual leaders, this title in English usage generally refers to the supreme earthly head of the Roman Catholic Church. The title itself has been used officially by the head of the Roman Catholic Church since the tenure of Pope Siricius. There is no official list of popes, but the Annuario Pontificio, published every year by the Vatican, contains a list that is generally considered to be the most authoritative.