The Byzantine Church after the Schism

In July 1054 a papal legate laid a bull of excommunication on the altar of Hagia Sophia during the liturgy and walked out. The patriarch, Michael Cerularius, condemned him in return. Neither man believed he had divided Christendom, and for a long time nobody treated the breach as final. But the estrangement between the Greek and Latin churches did not heal, and it hardened catastrophically in 1204, when a crusading army sacked Constantinople, installed a Latin patriarch, and drove the imperial church into exile at Nicaea for nearly sixty years. The Byzantines returned in 1261. In 1274, needing Western help against his enemies, Emperor Michael VIII accepted union with Rome at the Second Council of Lyon. His own clergy and monks refused it, and the union collapsed.