Pope Gregory XII in the context of Antipope Alexander V

The Western Schism, also known as the Great Divide, the Great Occidental Schism, the Schism of 1378, or the Great Western Schism (Latin: Magnum schisma occidentale, Ecclesiae occidentalis schisma), was a split within the Catholic Church lasting from 20 September 1378 to 11 November 1417, in which bishops residing in Rome and Avignon simultaneously claimed to be the true pope, and were eventually joined by a line of Pisan claimants in 1409. The event was driven by international rivalries, personalities and political allegiances, with the Avignon Papacy in particular being closely tied to the French monarchy.

The papacy had resided in Avignon since 1309, but Pope Gregory XI returned to Rome in 1377. The Catholic Church split in September 1378, when, following Gregory XI's death and Urban VI's subsequent election, a group of French cardinals declared his election invalid due to intimidation and violence and, in the presence of three Italian cardinals, elected Clement VII, who claimed to be the true pope. As Roman claimant, Urban VI was succeeded by Boniface IX, Innocent VII and Gregory XII. Clement VII was succeeded as Avignon claimant by Benedict XIII.

Pope Eugene IV (Latin: Eugenius IV; Italian: Eugenio IV; 1383 – 23 February 1447), born Gabriele Condulmer, was head of the Catholic Church and ruler of the Papal States from 11 March 1431 to his death in February 1447. Condulmer was a Venetian, and a nephew of Pope Gregory XII. In 1431, he was elected pope.

His tenure was marked by conflict: first with the Colonna, relatives of his predecessor Pope Martin V; and later with the Conciliar movement. In 1434, after a complaint by bishop of the Canary Islands Fernando Calvetos, Eugene IV issued the bull "Creator Omnium", rescinding any recognition of Portugal's right to conquer the islands, and rescinding any right to Christianize their native populations. Eugene also resisted slavery: he excommunicated anyone who had enslaved newly-converted Christians, such penalty to remain in place until the enslaved were restored to their liberty and possessions. Eugene initially sought to protect the Jews, and was quite active against a rampant societal anti-semitism—he issued decrees protecting their rights, opposing forced baptisms, and permitting wider economic activity. In 1442, however, he promulgated the bull Dudum ad nostram audientiam, which was later used as the legal basis for the creation of Jewish ghettos in Europe. In 1443, Eugene decided to take a neutral position on territorial disputes between Castile and Portugal and regarding rights claimed along the coast of Africa.

The Council of Pisa (Latin: Concilium Pisarum; Italian: Concilio di Pisa, also nicknamed the conciliabolo, "secret meeting", by those who considered it illegitimate) was a controversial council held in 1409. It attempted to end the Western Schism by deposing both Benedict XIII (Avignon) and Gregory XII (Rome) for schism and manifest heresy. The College of Cardinals, composed of members from both the Avignon Obedience and the Roman Obedience, who were recognized by each other and by the Council, then elected a third papal claimant, Alexander V, who lived only a few months. He was succeeded by John XXIII.

The resignation of Pope Benedict XVI took effect on 28 February 2013 at 20:00 Roman-Vatican Time, following Benedict XVI's announcement of the same on 11 February. It made him the first pope to relinquish the office since Gregory XII was forced to resign in 1415 to end the Western Schism, and the first pope to voluntarily resign since Celestine V in 1294.

All other popes in the modern era have held the position from election until death. Benedict resigned at the age of 85, citing declining health due to old age. The conclave to select his successor began on 12 March 2013 and on 13 March 2013 elected cardinal Jorge Mario Bergoglio, Archbishop of Buenos Aires, Argentina, who took the name of Francis.