Ibas of Edessa

Ibas served as Bishop of Edessa from 435 until his death on 28 October 457. Before his episcopate he was a presbyter and teacher in Edessa who championed the Antiochene Christology of Theodore of Mopsuestia and translated Theodore's theological works into Syriac, making them foundational texts for the Syriac-speaking Church of the East. His association with the directorship of the School of Edessa is attested in older sources but is disputed in modern scholarship (notably A. Becker), and should be treated as uncertain. His 433 letter to a correspondent known as "Mari" — possibly a proper name, though some scholars read "Mari" as the Syriac honorific "My Lord," leaving the recipient's identity uncertain — is his sole surviving authentic writing; it sharply criticizes Cyril of Alexandria's theology and offers a firsthand account of the Council of Ephesus (431) and the subsequent Formula of Reunion. The recipient is described in sources as bishop of Hardashir (Ardashir/Veh-Ardashir, near Seleucia-Ctesiphon in Persia, modern Iraq). Ibas was first deposed on 1 January 448 by imperial order following accusations by his own clergy, with Nonnus of Edessa enthroned as his replacement on 21 July 448; the Second Synod of Ephesus (the "Robber Synod") of 449 then confirmed the deposition in his absence while he was imprisoned in Antioch. He was restored to his see by the Council of Chalcedon in 451, having agreed to anathematize Nestorius and Eutyches and accept the Tome of Leo. A century after his death, the letter to Mari was condemned posthumously as one of the Three Chapters at the Second Council of Constantinople (553), making Ibas a pivotal — and posthumously contested — figure in fifth- and sixth-century Christological controversy.