Studites, Theodore, a violent opponent of the iconoclasts in the early Church, was born in Constantinople, A.D. 759, entered the Convent of Studium in 781, and was made its abbot, or archimandrite, in 794. He soon came into conflict with the emperor Constantine Copronymus-- a violent iconoclast, who had separated from his consort and was about to marry Theodora-- and denounced the ban against him, besides severing his relations with the patriarch Tarasius, because the latter would not proceed energetically against the emperor. Constantine thereupon banished him to Thessalonica. When image worship was restored, Theodore was recalled and received into favor; but he became involved in fresh troubles, this time with the emperor Nicephorus, who caused him to be imprisoned and transported to an island near Constantinople, where he remained until reinstated in his office by Michael Rhangave. When Leo the Armenian renewed the attack on image worship (813), Studites at once rose against him with his accustomed zeal; the emperor caused him to be warned, but without result, and then called a synod at Constantinople which prohibited iconolatry (815), after which he took energetic measures for its repression. Studites was confined at Mesope, and afterwards (819) at Smyrna. Balbus gave him his liberty, in 821 and permitted the adoration of images in private; but the zeal of Studites soon compelled his renewed banishment from Constantinople. He took up his abode on the island of Chalcis, and died there, Nov. 11, 826. He composed a number of letters, poems, and other writings against the iconoclasts, for which see Bellarmine, De Scriptoribus Eccles. [Colon. 1684], p. 151. Part 5 of Jacques Sirmond's Opera Varia (Venet. 1728) is almost exclusively devoted to Theodore Studites and his writings. Comp. also the literary references in Gieseler, Kirchengeschichte (Bonn, 1846), 2, 1, 10 sq.