The term Great Schism refers to either of two splits in the history of Christianity:

• Most commonly, it refers to the great East-West Schism, the event that separated Eastern Orthodoxy and Western Roman Catholicism in the eleventh century (1054).
• In the second schism within the Catholic Church, the Western Schism in the fourteenth century (1378), three (claimant) popes were elected at the same time.