- Union of the Churches
- The separation of the eastern and western churches had its origins as far back as the foundation of Constantinople (q.v.) in 330, which diminished the importance of Rome (q.v.). It also had its origins in the Council of Chalcedon (q.v.) which seemed to threaten the stature of the bishop (q.v.) of Rome, and in the gradual diminution of Byzantine power in Italy (q.v.) beginning with the Lombard (q.v.) invasion of 568. Differences in ritual and practice were also important, including the western use of azyma, the filioque, and papal primacy (qq.v.). The intolerance of western church reformers in the 11th century was reflected in the person of Humbert (q.v.), who played a chief role in instigating the schism of 1054 (q.v.). In retrospect, it was the conquest of Constantinople by the Fourth Crusade (q.v.) that made reconciliation with the West impossible. Moreover, efforts to heal the schism were intertwined with the Byzantine state's need of western military aid against the Seljuks and Ottomans (qq.v.); inevitably this meant a Crusade, which only the papacy (q.v.) could proclaim. The union of the churches proclaimed at the Council of Lyons (q.v.) in 1274, and subsequently at the Council of Ferrara-Florence (q.v.) in 1439, failed to gain popular support, much less any realistic military aid, as seen in the failed Crusade of Varna (q.v.).
Historical Dictionary of Byzantium . John H. Rosser .