Antipope

An antipope is a person who, in opposition to a sitting Bishop of Rome, makes a widely accepted claim to be the Pope. In the past, antipopes were typically those supported by a fairly significant faction of cardinals and kingdoms. Persons who claim to be the pope but have few followers, such as the modern sedevacantist antipopes, are not generally classified as antipopes, and therefore are ignored for regnal numbering.

Saint Hippolytus (d. 235) is commonly considered to be the earliest antipope, as he protested against Pope Callixtus I and headed a separate group within the Church in Rome. Hippolytus was later reconciled to Callixtus's second successor, Pope Pontian, when both were condemned to the mines on the island of Sardinia. He has been canonized by the Church. Whether two or more persons have been confused in this account of Hippolytus, and whether Hippolytus actually declared himself to be the Bishop of Rome, remains unclear, especially since no such claim has been cited in the writings attributed to him.

Eusebius of Caesarea quotes from an unnamed earlier writer the story of a Natalius who accepted to be bishop of a heretical group at Rome, but who soon repented and tearfully begged Pope Zephyrinus (Pope from 199 to 217) to receive him into communion. If Natalius claimed to be Bishop of Rome rather than only of a small group in the city, he could be considered an antipope earlier than Hippolytus and indeed the first antipope.

Novatian (d. 258), another third-century figure, certainly claimed the See of Rome in opposition to Pope Cornelius, and if Natalius and Hippolytus were excluded because of the uncertainties concerning them, Novatian could then be said to be the first antipope.

The period in which antipopes were most numerous was during the struggles between the popes and the Holy Roman Emperors of the 11th and 12th centuries. The emperors frequently imposed their own nominees to further their own causes. The popes, likewise, sometimes sponsored rival imperial claimants in Germany to overcome a particular emperor.

The Great Western Schism – which began in 1378, when the French cardinals, claiming that the election of Pope Urban VI was invalid, elected Clement VII as Pope – led to two, and eventually three, rival lines of claimants to papacy: the Roman line, the Avignon line (Clement VII took up residence in Avignon, France), and the Pisan line. The last-mentioned line was named after the town of Pisa, Italy, where the council that elected Alexander V as a third claimant was held. To end the schism, in May 1415, the Council of Constance deposed John XXIII of the Pisan line, whose claim to legitimacy was based on a council's choice. Pope Gregory XII of the Roman line resigned in July 1415. In 1417, the Council of Florence also formally deposed Benedict XIII of the Avignon line, but he refused to resign. Afterwards, Pope Martin V was elected and was accepted everywhere except in the small and rapidly diminishing area that remained faithful to Benedict XIII. The scandal of the Great Schism created anti-papal sentiment, and fed into the Protestant Reformation at the turn of the 16th century.