Born between 810 and 827, in Constantinople; died between 891 and 897. Byzantine ecclesiastical and political figure, writer.
As patriarch of Constantinople from 858 to 867 and again from 877 to 886, Photius criticized the despotism of the emperor and asserted that the patriarch and the emperor were equal in authority. Photius did much to extend the influence of the Byzantine church to the Slavic lands of Bulgaria, Moravia, and Rus’. In so doing, however, he came into conflict with the papacy and thus helped precipitate the Great Eastern Schism. Of Photius’ many works, the most important was Myriobiblon (Bibliotheca), the first medieval bibliographical work to contain elements of literary criticism. He also wrote theological treatises on such subjects as the Paulician heresy; sermons, including two that mention the attack of Rus’ on Constantinople in 860; and letters, which are important sources on the domestic history and foreign policy of Byzantium. Photius was deposed in 886 by Emperor Leo VI and died in exile.