The Great Schism

schism · 1054 · Constantinople

On 16 July 1054 Cardinal Humbert laid a bull of excommunication against the patriarch Michael Cerularius on the altar of Hagia Sophia; on the 24th Cerularius' synod anathematized the legates in return. The anathemas were personal, and few that year thought the breach final — but after centuries of drift over the filioque, the azymes and jurisdiction, 1054 became the emblem of a separation not yet healed. The legates had been sent by Leo IX.

The East–West Schism, also known as the Great Schism or the Schism of 1054, is the break of communion between the Catholic Church and the Eastern Orthodox Church since 1054. A series of ecclesiastical differences, theological disputes and geopolitical tensions between the Greek East and Latin West preceded the formal split in 1054. Prominent among these were the Filioque clause of the Nicene Creed, whether leavened or unleavened bread should be used in the Eucharist, iconoclasm, the coronation of Charlemagne as emperor of the Romans in 800, the pope's claim to universal jurisdiction, and the place of the See of Constantinople in relation to the pentarchy. Although 1054 has become conventional, various scholars have proposed different dates for the Great Schism, including 1009, 1204, 1277, and 1484.

Legates in Constantinople to settle the azymes dispute and secure an alliance — met by a patriarch who would not bend.

Mutual anathemas, personal in law but final in memory: 1054 became the emblem of the East–West separation.

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