Photian Schism, a 9th-century-ce controversy between Eastern and Western Christianity that was precipitated by the opposition of the Roman pope to the appointment by the Byzantine emperor Michael III of the lay scholar St. Photius to the patriarchate of Constantinople. The controversy also involved Eastern and Western ecclesiastical jurisdictional rights in the Bulgarian church, as well as a doctrinal dispute over the Filioque (“and from the Son”) clause that had been added to the Nicene Creed by the Latin church.
The end of iconoclasm in 843 left a legacy of faction. Ignatius, patriarch of Constantinople intermittently from 847 to 877, was exiled by the Byzantine government in 858. Michael III selected Photius, head of the imperial chancery, to replace him; Photius was elected patriarch and ordained within six days. Influenced by Ignatius’s supporters, Pope Nicholas I (reigned 858–867) challenged Photius’s elevation to the patriarchate, deploring as uncanonical the speed with which he had been advanced through the successive ranks of the hierarchy. The new patriarch, however, refused to bow.
Nicholas had long been angered by Byzantine missions among the Bulgars, whom he regarded as belonging to his sphere. When Nicholas wrote to the Bulgars attacking Greek practices, Photius replied by accusing the West of heretically altering the creed in saying that the Holy Spirit proceeds from the Father and from the Son (Filioque). When Nicholas excommunicated Photius, the patriarch arranged a council, presided by Michael III, in 867 and declared Nicholas deposed. His position, however, was not strong enough for such impudence.
Shortly thereafter a new emperor, Basil the Macedonian (who murdered Michael on his bloody path to the throne), reinstated Ignatius. In 869 Nicholas’s successor, Adrian II (reigned 867–872), again condemned Photius—a stance confirmed at the Fourth Council of Constantinople. Adrian also sent legates to Constantinople to extort submission to papal supremacy from the Greeks. The Greeks resented the papal demands, and, when Ignatius died in 877, Photius quietly became patriarch again. Rome (at that moment needing Byzantine military support against Muslims in Sicily and southern Italy) reluctantly agreed to recognize Photius but on the condition of an apology and of the withdrawal of Greek missions to the Bulgars. Photius acknowledged Rome as the first see of Christendom, discreetly said nothing explicitly against the Filioque clause, and agreed to the provision that the Bulgars could be put under Roman jurisdiction provided that Greek missions were allowed to continue. The schism was thus effectively resolved.
The key conflicts between the two sees were matters of ecclesiastical supremacy, the liturgy, and clerical discipline; behind those sources of division lay the question of jurisdiction over the converts in Bulgaria. And behind that question may be found centuries of growing separation between the minds and institutions of the eastern and the western Mediterranean worlds, symbolized in the roles assumed by two among the major protagonists in the Photian Schism. Indeed, the main issue was whether Rome possessed monarchical power of jurisdiction over all churches (as Nicholas and Adrian assumed), or whether Rome was the senior of five semi-independent patriarchates (as Photius and the Greeks thought) and therefore could not canonically interfere with the internal affairs of another patriarchate.