The Bishop of Rome. Successor of Saint Peter the Apostle. Chief pastor of the whole Church. Vicar of Christ on earth. Archbishop of the Roman Province. Primate of Italy and the adjacent islands. Patriarch of the Western Church. The adjective related to the pope is papal. The office or mission of the pope is the papacy. The period of his reign is a pontificate.
The Church's doctrine as to the pope was authoritatively declared in the First Vatican Council in the Constitution "Pastor Aeternus". The four chapters of that Constitution deal respectively with the office of Supreme Head conferred on Saint Peter, the perpetuity of this office in the person of the Roman pontiff, the pope's jurisdiction over the faithful, and his supreme authority to define in all questions of faith and morals.