The Great Eastern Schism is the name given to the separation of the Roman and Byzantine branches of the Christian church.

This separation of the Latin and Greek churches is sometimes dated from 1054, the date when Byzantine and Roman officials excommunicated each other. Actually, the break came about through a gradual process of estrangement that extended from the 9th to the 15th century.

Background of the Schism

Causes of the schism included political, cultural, economic, and social as well as theological differences that originated before 1000. The political unity of the Mediterranean world was shaken and finally destroyed through the barbarian invasions in the West and the rise of Islam in the East.

Communication between the Greek-speaking East and the Latin West broke down as church and other leaders in each no longer spoke or read the language of the other half of the Christian world.

Charlemagne and Adrian IIn 800 Charlemagne was crowned by the Pope as the new emperor of the Roman Empire, but he was not recognized by the Byzantine Greeks.

The court theologians of Charlemagne considered the Eastern Christians to be heretics because the latter refused to admit the word Filioque into the Creed, while the Greeks viewed the introduction of that doctrine into the Nicene-Constantinople Creed as unforgivable.

The development of church order in the West made the pope of Rome the strong monarchical bond of unity throughout the Western world.

The East had no comparable structure; the church was administered by a hierarchy whose members were considered equals.

Photius IEast-West issues crystallized in a quarrel between Photius, patriarch of Constantinople, and Pope Nicholas I, which resulted in the Photian schism (867).

Photius was eventually recognized by the pope as the legitimate successor of Patriarch Ignatius after the latter’s death in 877.

However, Photius had condemned the primacy of the pope of Rome and the use of the Filioque as unacceptable to the Christian East.

In the 11th century other factors aggravated these differences. In 1009 the Filioque clause was made an essential part of the Latin profession of faith. In retaliation the name of the pope of Rome was dropped from the diptychs, or lists of those patriarchs with whom a patriarchal church was in communion.

Under strong reforming popes such as Gregory VII, the papacy claimed jurisdiction over all Christian churches. This claim was ignored in the East.

The Normans conquered the southern part of Italy, which was under Byzantine control, and insisted on enforcing Latin customs.

Patriarch Michael Cerularius retaliated in 1052 by closing the Latin churches in Constantinople.

In 1054, Pope Leo IX sent three legates, led by Cardinal Humbert, to Cerularius.

On July 16, 1054, Humbert laid upon the altar of Hagia Sophia a bull of excommunication of Cerularius and his partisans.

Michael CerulariusCerularius summoned his 20 metropolitans and anathematized “the impious document and its authors.” This seemed to be more a personal quarrel than an excommunication, and friendly relations still continued between the churches.

Effect of the Crusades

The Latin Crusaders made the schism definitive. During the First Crusade (1098–1099) the Latins captured Antioch and Jerusalem and set up Latin patriarchates, which caused friction with the Oriental patriarchates. In 1204, during the Fourth Crusade, the Latins sacked Constantinople. Their swords finally cut Christendom into two distinct Roman and Orthodox parts.

Attempts at Reconciliation

Two attempts at reunion took place, one in 1274 at the Second Council of Lyons and the other in 1438–1439 at the Council of Florence. At both councils the Orthodox accepted the Latin papal claims and the doctrine of the Filioque, but the unions effected were mainly on paper. The masses of Christians, the monks, and the lower clergy were not ready for the healing of the schism.

On April 7, 1453, the Turks took Constantinople and the Byzantine Empire came to an end. The separation of East and West was accepted as a reality by both Orthodox and Catholics.