Event · 1054

Great Schism

The break between the churches of Rome and Constantinople, conventionally dated to 1054, which divided the Roman Catholic and Eastern Orthodox churches.

In 1054 papal legates led by Cardinal Humbert excommunicated Patriarch Michael Cerularius, who excommunicated them in return. The underlying issues were older: the authority of the pope, the Filioque, and differences in practice such as leavened or unleavened bread. The split hardened over time, especially after crusaders sacked Constantinople in 1204. In 1965 Pope Paul VI and Patriarch Athenagoras lifted the excommunications of 1054.