The Council of Pisa convenes, in an attempt to heal the Western Schism.

The Council of Pisa 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 Western Schism, also known as the Papal Schism, the Great Occidental Schism, the Schism of 1378, or the Great Schism, 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.