Eastern Orthodox And Roman Catholic Churches Are In A Schism
In the east of Europe was the Byzantine Empire, Christians who had long followed a separate Orthodox rite.
Since 1054 the Eastern Orthodox and Roman Catholic churches had been in schism, and it has been argued that the desire to impose Roman church authority in the east may have been one of the goals of the crusade, although it should be noted that Urban II, who actually launched the First Crusade, never refers to such a goal in his letters on crusading. The Seljuk Turks had taken over almost all of Anatolia after the Byzantine defeat at Manzikert in 1071, with the result that on the eve of the Council of Clermont, the total territory controlled by the Byzantine Empire had fallen by more than half. By the time of Emperor Alexius I Comnenus, the Byzantine Empire was largely confined to Balkan Europe and the northwestern fringe of Anatolia, and faced Norman enemies in the west as well as Turks in the east. In response to the defeat of Manzikert and subsequent Byzantine losses in Anatolia in 1074, Pope Gregory VII had called for the milites Christi ("soldiers of Christ") to go to Byzantium's aid. This call, while largely ignored and even opposed, nevertheless focused a great deal of attention on the east.
The East-West Schism, or the Great Schism, divided medieval Christendom into Eastern (Greek) and Western (Latin) branches, which later became known as the Eastern Orthodox Church and the Roman Catholic Church, respectively. Relations between East and West had long been embittered by political and ecclesiastical differences and theological disputes. Pope Leo IX and Patriarch of Constantinople Michael Cerularius heightened the conflict by suppressing Greek and Latin in their respective domains. In 1054, Roman legates traveled to Cerularius to deny him the title Ecumenical Patriarch and to insist that he recognize the Church of Rome's claim to be the head and mother of the churches. Cerularius refused. The leader of the Latin contingent, Cardinal Humbert excommunicated Cerularius, while Cerularius in return excommunicated Cardinal Humbert and other legates.