Definition
The Orthodox-Catholic split, also called the Great Schism, was the formal division of Christianity in 1054 into two branches: the Eastern Orthodox Church, centered on Constantinople, and the Roman Catholic Church, centered on Rome.
The break was the culmination of centuries of growing political, cultural, theological, and linguistic distance between the Greek-speaking East and the Latin-speaking West.
Why it matters
How it works
The schism grew from accumulated differences rather than a single event. The West asserted that the Pope held supreme authority over all Christians, while the East regarded the major bishops as equals. Theological disputes, especially over the wording of the Nicene Creed, and contrasting practices and languages widened the gap. In 1054 mutual excommunications between Rome and Constantinople formalized the break. Later events, including the sack of Constantinople by Western crusaders, hardened the divide into a permanent separation.