SAHAK (ISAAC) I, the GREAT. — Famous Armenian katholikos, born around the middle of the 4th century and probably died on 7 September 439. He was the son of the katholikos Nerses the Great
and the true patriarch of Armenian letters. Under his protection and that of Mesrop, the “holy translators” produced the translation of Sacred Scripture and of important Greek and Syriac writings.
S. became katholikos of Armenia around 390 and remained there until 420, when he was deposed by the Persian emperor Iezdegerd I because of the orthodoxy maintained by S. both against paganism and against heresy. S. nevertheless remained, as before, the spiritual head of Armenia. A few years later, S. was warned by the bishop of Edessa, Rabbôlà, of the danger posed by the teaching of Theodore of Mopsuestia, while other bishops were recommending it to him. A national Armenian synod, probably in 435, decided to request precise information from Proclus of Constantinople, thereby prompting his Tomus ad Armenios. S. replied to Proclus and Acacius of Melitene, full of enthusiasm for orthodoxy and acknowledging the title of Theotokos to the Madonna. The Armenians venerate S. as a saint.
S. does not seem to have been a particularly prolific author, although Koriun attributes “many biblical commentaries” to him; Moses of Chorene preserved three letters (Storia Arm. 3, 57). Those addressed to Proclus and Acacius are found in the Book of Letters (Tiflis 1901); the one to Proclus was also published by A. Vardinian, in Wiener Zeitsch. für die Kunde des Morgenlandes, 27 (1913), pp. 415–41. A canonical constitution attributed to S. (cf. F. C. Conybeare, The armenian Canons of St. S., in The American Journal of Theol., 2 [1898], pp. 838–48) probably contains an authentic core.
Ignazio Ortiz de Urbina