split within the Catholic Church from 1378 to 1417, in which bishops in Rome and Avignon both claimed to be the pope, joined by a third line of Pisan popes in 1409
|Popes of the Western Schism|
- "Western Schism," Catholic Encyclopedia (2009); retrieved 2011-11-29.
. Catholic Encyclopedia. New York: Robert Appleton Company. 1913.