The Western Schism, also called Papal Schism, The Vatican Standoff, Great Occidental Schism and Schism of 1378 (Latin: Magnum schisma occidentale, Ecclesiae occidentalis schisma), was a split within the Catholic Church lasting from 1378 to 1417 in which bishops residing in Rome and Avignon both claimed to be the true pope, joined by a third line of Pisan popes in 1409. The schism was driven by personalities and political allegiances, with the Avignon papacy being closely associated with the French monarchy. These rival claims to the papal throne damaged the prestige of the office.
|Motive||International rivalries in Catholic Europe|
|Outcome||Reunification of Catholic Church in 1415–1429|
The papacy had resided in Avignon since 1309, but Pope Gregory XI returned to Rome in 1377. However, the Catholic Church split in 1378 when the College of Cardinals elected both Urban VI and Clement VII pope within six months of Gregory XI's death. After several attempts at reconciliation, the Council of Pisa (1409) declared that both popes were illegitimate and elected a third pope. The schism was finally resolved when the Pisan pope John XXIII called the Council of Constance (1414–1418). The Council arranged the abdication of both the Roman pope Gregory XII and the Pisan pope John XXIII, excommunicated the Avignon pope Benedict XIII, and elected Martin V as the new pope reigning from Rome.
The affair is sometimes referred to as the Great Schism, although this term is also used for the East–West Schism of 1054 between the Churches remaining in communion with the See of Rome and the Eastern Orthodox Churches.