W:Western Schism

The Western Schism, also called Papal Schism, Great Occidental Schism and Schism of 1378, was a split within the Catholic Church lasting from 1378 to 1417 in which two, by 1410 three men simultaneously claimed to be the true pope, and each excommunicated one another. Driven by authoritative politics rather than any theological disagreement, the schism was ended by the Council of Constance (1414–1418). For a time these rival claims to the papal throne damaged the reputation of the office.

The affair is sometimes referred to as the Great Schism, although this term is typically reserved for the more enduring East–West Schism of 1054 between the Western Churches answering to the Roman Catholic Church and the Orthodox Church.