may 7, 1054 - Schism between Eastern and Western Christian Churches
This mutual excommunication marks the formal break between Eastern and Western Christianity. That break has never been healed. The hostility and split were intensified when, during the 1204 Crusade, the crusaders sacked and pillaged Constantinople on Good Friday. So horrific and inexcusable was this event that the break between Eastern and Western Christianity was final and complete. Islam also had a devastating effect on the Eastern Church.
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