The Great Schism: How the Church Split in Half

In 1054 a cardinal laid a bull of excommunication on the altar of Hagia Sophia, issued in the name of a pope who had been dead for three months, which under the Church's own law made it invalid. This is how Christianity actually split: seven centuries of linguistic and political drift, one word added to the creed, two men with no diplomatic instinct, and the sack of Constantinople in 1204 that made the breach permanent. Plus what the 1965 joint declaration did and did not undo. 0:00 A document on an altar 0:55 Two halves drifting 3:22 The word 4:51 1054 6:16 Why it didn't feel like a schism 7:45 What has changed 9:10 How small the hinge was 10:37 Next time Sources: the bull of Cardinal Humbert of Silva Candida (1054) and the synodal response of Patriarch Michael Cerularius; the Catholic-Orthodox Joint Declaration of 7 December 1965; contemporary accounts of the Fourth Crusade and the sack of Constantinople (1204); standard histories of the filioque controversy and of the reunion councils of Lyon and Florence.