Theodore of Studium, Saint (stōˈdēəm) [key], 759–826, Byzantine Greek monastic reformer, also called St. Theodore the Studite. As an abbot he was early exiled for opposing the marriage of Emperor Constantine VI to his mistress Theodota. In 799 he entered the Studium monastery, which he reformed and made the model monastery of the Byzantine rite. He was exiled again (809–11) after long quarrels with Nicephorus I, and by Leo V when he opposed him (814). His influence was critical in the history of the Basilian monks. His writings deal with the monastic life and with iconoclasm. St. Theodore wrote many hymns, and his letters are extant.
See A. Gardner, Theodore of Studium (1905, repr. 1974). Feast: Nov. 11.