The Western Schism, also called Great Western Schism, or Schism of 1378, was a division in the Roman Catholic Church that occurred in 1378. During this period, there were three popes who claimed the papacy. The Western Schism was mostly driven by politics, rather than a religious dispute between the popes.
The last French pope who resided in Avignon was Gregory XI (1371-1378). In 1377, he made a decision to return to Rome, thus ending the Avignon papacy, which was infamous for the corruption that it helped spread over western Christendom.
According to the Great Schism website, when Gregory XI died in 1378, the Roman people demanded that the French cardinals elect a Roman, or at least Italian, pope. In 1378, a Neapolitan pope, Urban VI, who was impulsive, reformist, and hostile, was elected.
It did not take long for the cardinals to regret their decision. The policies of the new pope made them believe he was mentally ill. Although they argued that the appointment of Urban VI was invalid because it had been made in an environment of fear, the pope refused to step down.
Thus, the majority of cardinals moved from Rome to Anagni and elected Robert of Geneva as Clement VII in 1378. Clement VII took up residence at Avignon, even though Urban VI was still considered the legitimate pope. According to Louis Salembier, this double election threw the Catholic Church into turmoil. The dual papacy encouraged political antagonism that divided Europe because the leaders of the those countries had to choose which pope they would recognize.
Both popes assigned their own cardinals, created their curia, and implemented fiscal policies. The spectacle of rival popes fighting for authority resulted in the papacy losing its prestige. Even when the Roman and the Avignon popes died, the schism continued, further sustained by national rivalries.
The new popes were Boniface IX, who resided in Rome, and Benedict XIII, who resided in Avignon. Several attempts to bring an end to the conflict were made, but the outcome was the election of a third pope, Alexander V, by the Council of Pisa in 1409. The Roman and the Avignon popes, who refused to answer the summons to appear, were deposed by the Council in 1409. However, there were still three popes, none of whom wanted to lose his power.
In 1414, a council was held at Constance to settle the Great Western Schism. The Council secured the resignations of two popes, but the third pope, Benedict XIII, was uneager to resign. In 1417, Pope Martin V was elected by the Council of Constance. Despite the fact that he was not recognized by the Crown of Aragon, which still recognized Benedict XIII, the schism officially came to an end in 1417.
The significance of the Papal Schism can hardly be overestimated. The effects of the Western Schism on the Catholic Church were so profound that they were felt for years to come. The theory of conciliarism was developed, which helped the Council of Constance put an end to the schism. This new movement showed that a general council had the power to correct and even depose a pope. A major decline in the Catholic Church’s moral occurred, and the church authority was weakened dramatically.