THEODORE III. (1661-1682), tsar of Russia, was the eldest surviving son of Tsar Alexius and Maria Miloslayskaya. In 1676 he succeeded his father. He had received an excellent education at the hands of Simeon Polotsky, the most learned Slavonic monk of the day, knew Polish, and even possessed the unusual accom plishment of Latin; but, disfigured and half paralyzed by disease, he had been an invalid from his birth. In 1679 he married his first cousin Agatha and assumed the sceptre. His native energy was not crushed by his disabilities ; and he soon proved as thorough a reformer as a man incompetent to lead armies and obliged to issue his orders from his litter, or his bed-chamber, could be. His consort, Agatha, shared his progressive views. On her death (July 4, 1680 Theodore married Martha Apraksina. He died on April 27, 1682, without issue.
made a tour of the whole of Anglo-Saxon England, reforming abuses and giving instruction as to the monastic rule and the canonical Easter. Bede also declares that he was the first arch bishop to whom all the "church of the Angles" submitted.
In 673 Theodore presided at the first synod of the clergy in England which was held at Hertford. Various disciplinary regu lations were emphasized, and an annual meeting arranged at a place called Cloveshoe. After this council Theodore revived the East Saxon bishopric, to which he appointed Earconwald. Soon after the first expulsion of Wilfrid in 678 he divided the North umbrian diocese, appointing Trumwine bishop to the Picts. This led to a quarrel with Wilfrid which was not finally settled until 686-687. In 679 Theodore intervened to make peace between Ecgfrith of Northumbria and Aethelred of Mercia. He presided at other synods held in 68o at Hatfield and in 684 at Twyford, and died in 69o. A penitential composed under Theodore's direc tion is still extant.
See Bede, Hist. Eccl., edited by C. Plummer (Oxford, 1896) ; Eddius, Vita Wilfridii in J. Raine's Historians of the Church of York, vol. i. (London, 1879) ; Anglo-Saxon Chronicle, edited by Earle and Plummer (Oxford, 1899) ; Haddan and Stubbs, Councils and Eccle siastical Documents (Oxford, 1869-78), iii. 173-213.