Early Life and Education
Theodore was born around 602 in Tarsus in Cilicia, a Greek-speaking diocese of the Byzantine Empire. His childhood coincided with major warfare between the Roman and Persian empires, including the capture of Antioch, Damascus, and Jerusalem in 613 and 614.
His studies likely took place at Antioch, following that city's distinctive exegetical tradition, and he acquired knowledge of Syriac culture and language. He later relocated to Constantinople, where his studies ranged across astronomy, ecclesiastical computus, medicine, Roman civil law, and Greek rhetoric and philosophy. Before the 660s he moved to Rome and joined an Eastern monastic community, where he added a mastery of Latin literature to his Greek learning.
Reform of the English Church
Upon arriving in England, Theodore conducted a survey of the English Church and appointed bishops to vacant sees. In 672 he convened the Synod of Hertford, the first national council of the English Church, which legislated on the calculation of Easter, episcopal authority, the conduct of itinerant monks, the regular convening of synods, and questions of marriage and consanguinity.
He reorganized the diocesan map, most controversially by subdividing the large diocese of Northumbria, a measure that brought him into conflict with Bishop Wilfrid of York, whom he deposed in 678 before the dispute was resolved in 686-687. He also resolved an earlier dispute in Northumbria involving the bishops Wilfrid and Chad, regularizing Chad's consecration. In 679 he intervened diplomatically to prevent the escalation of war between Northumbria and Mercia after the death of Aelfwine in battle, arranging a compensation payment. Through such organizational and canonical work the English Church became united in a way the separate kingdoms were not, and the diocesan structures he established long served as the basis for church administration in England.
The School at Canterbury
Together with the abbot Hadrian, Theodore established a school at Canterbury that taught both Greek and Latin and trained students from both the Celtic and Roman traditions. Its curriculum included Holy Scriptures, poetry, astronomy, the calculation of the church calendar, and sacred music.
Theodore introduced knowledge of the Eastern saints to the West and may have been responsible for introducing the Litany of the Saints to Western liturgy. A penitential known as the Paenitentiale Theodori was composed under his direction. The school became a center of learning whose pupils carried his curriculum throughout southern England.
Relics and Veneration
Theodore was buried at Canterbury in the church then called St. Peter's, later known as St Augustine's Abbey, and his body was reported to have remained incorrupt for a long time. His canonization is pre-Congregation, and he is listed in the Roman Martyrology.
He is venerated in the Eastern Orthodox Church, the Catholic Church, and the Anglican Communion, with his feast kept on 19 September; Canterbury also observed a secondary commemoration on 26 March, the date of his ordination.
