World Religions › Medieval
Great Schism between East and West
1054· Event· Judaism, Christianity & Islam
Historical recordConfirmed by archaeology, outside sources or contemporary records.
The 1054 break between the Greek-speaking churches of the East, led from Constantinople, and the Latin Church of the West, led by Rome.
See it on the World Religions map →What it is
East and West had drifted apart for centuries over language, politics and theology. Key disputes were the pope's claim to authority over all bishops and the Latin addition of filioque ('and the Son') to the Nicene Creed. In July 1054 the papal envoy Cardinal Humbert laid a bull excommunicating Patriarch Michael Cerularius on the altar of Hagia Sophia; the patriarch excommunicated the envoys in return. The Crusaders' sack of Constantinople in 1204 made the break lasting.
Why it matters
It separated Christianity's two largest ancient branches, Catholic and Orthodox, and deepened Europe's divide between the Latin West and Orthodox East.
Sources and history
The 1054 excommunication documents and letters by Humbert and Cerularius survive; in 1965 Pope Paul VI and Patriarch Athenagoras formally lifted the mutual excommunications.
Questions and debates
Was 1054 the decisive break or one moment in a slow drift? Pope Leo IX had died months before, so the envoys' authority was doubtful; 1204 arguably mattered more.
Inside this (3)
Connections (4)
▸Great Schism between East and West created the separate Eastern Orthodox ChurchHistorical record
The connection
The 1054 excommunications and the 1204 sack of Constantinople left the Eastern churches, led by their patriarchs, lastingly out of communion with Rome. From then on Orthodoxy developed as its own body, rejecting papal supremacy and filioque, and keeping its own liturgy, calendar and married parish clergy.
When and where
Constantinople and Rome, 1054; hardened in 1204; attempts at reunion at Lyon (1274) and Florence (1439) failed.
Historical evidence
Council records of Lyon and Florence, whose reunion decrees Orthodox clergy and people rejected; the 1965 joint declaration lifting the excommunications.
Questions and debates
The Orthodox see Rome as having left the original church, Catholics see the reverse; dialogue continues, but full communion has not been restored.
▸The Crusades deepened Great Schism between East and WestHistorical record
The connection
The 1054 split between Rome and Constantinople was not at first seen as final. The Crusades, launched partly to help Byzantium, bred mistrust as Latin armies installed their own clergy in Eastern cities. The Fourth Crusade's sack of Constantinople in 1204, with churches looted, turned the split into lasting hostility among Orthodox Christians.
When and where
Antioch from 1098 and Constantinople in April 1204; crusaders, Venice and the Byzantines. Pope John Paul II apologized in 2001; Patriarch Bartholomew accepted in 2004.
Historical evidence
Byzantine accounts, such as Niketas Choniates' history of the sack; crusader chronicles by Villehardouin; and looted treasures still in Venice, such as St. Mark's horses.
Questions and debates
Historians debate whether the schism was already beyond repair before 1204, and whether the Fourth Crusade's diversion to Constantinople was planned or accidental.
▸Second Vatican Council ended with lifting the 1054 excommunications of the Great Schism between East and WestHistorical record
The connection
The council invited Orthodox observers, and its decree on ecumenism praised the Eastern churches. Pope Paul VI met Ecumenical Patriarch Athenagoras I in Jerusalem in 1964, the first such meeting in five centuries. On December 7, 1965, a joint declaration removed the 1054 excommunications 'from memory', though full communion was not restored.
When and where
Rome and Istanbul, December 7, 1965, read simultaneously the day before the council closed; Pope Paul VI and Patriarch Athenagoras I.
Historical evidence
The text of the 1965 Catholic–Orthodox joint declaration, and records and photographs of the 1964 Jerusalem meeting.
Questions and debates
Whether reunion is achievable remains open; papal authority and the filioque clause are still unresolved in joint theological talks running since 1980.
▸Great Schism between East and West divided ChristianityHistorical record
The connection
Long-growing differences between the Latin West, led by the pope in Rome, and the Greek East, centered on Constantinople, split Christianity in two. They disputed the pope's authority, the Creed's 'filioque' phrase about the Holy Spirit, and practices such as leavened bread. The resulting Catholic and Eastern Orthodox churches remain separate today.
When and where
Constantinople, 1054: papal legates and Patriarch Michael Cerularius excommunicated each other. The Crusaders' sack of Constantinople in 1204 deepened the break.
Historical evidence
The excommunication documents survive; Pope Paul VI and Patriarch Athenagoras formally lifted the mutual excommunications in 1965.
Questions and debates
Historians debate whether 1054 marks the real split or one episode in a separation that unfolded over centuries; reunion talks continue.