Dictionary of Christian Biography and Literature to the End of the Sixth Century/Isaacus I, catholicos of Greater Armenia, Saint
Isaacus (7) I., St. (Sahag the Great, Parthev the Parthian), catholicos of the church of Greater Armenia for 40 or 51 years, 390–441. Moses of Khorene states that he belonged to the house of the founder of the Armenian church, Gregory the Illuminator. His long patriarchate is remarkable for the invention of the Armenian characters by Mesrob, the translation of the Scriptures into the Armenian language, and the commencement of the golden age of Armenian literature; for the revision of the Armenian liturgy, first translated from the Greek by Gregory, which has continued unaltered ever since in the Armeno-Gregorian church; and for the destruction of the independence of Armenia. At the commencement of his patriarchate Isaac visited the Persian king at Ctesiphon; where, on behalf of his sovereign, he acknowledged Armenia to be tributary to Persia. Owng to the troubled state of the country he was virtually ruler for several years. In 428, from which date Armenian chronology becomes more certain (St. Martin, Mém. sur l’Arménie, i. 320, n.), the Persian king deposed Ardaces IV., the last of the Armenian Arsacidae, and Isaac retired into Western Armenia, either by order of the Persian monarch or through the enmity of the satraps of his own country, whom it is said he had offended by refusing to join in their plans. Whilst in Western Armenia (428–439) he sent Mesrob to Constantinople with letters to Theodosius II., and the general Anatolius, who was commissioned by the emperor to build the city of Theodosiopolis (called Garin by the Armenians, Erzeroum by the Turks), near the sources of the Euphrates, as a place of refuge for Isaac. Meanwhile the Persian kings set up others as patriarchs in his, stead, but at length
the Armenian satraps repented and invited Isaac to resume his throne. This he refused to do, but appointed one administrator in his stead, according to some Mastentzes, according to Moses of Khorene Samuel, nominated by the Persian king. After the death of his vicar he seems to have partially resumed his episcopal functions over the whole Armenian community. On account of the patriarch's expulsion, the archbp. of Cappadocian Caesarea disallowed the ordination of bishops, which had been conceded to Isaac; but by the influence of the Persians all connexion between Armenia and Caesarea was from this time forth broken off—a fact which tended towards the isolation of the Armenian church. Isaac did not attend the general council of Ephesus. He died at the age of 110 years, being the last Armenian patriarch of the family of Gregory the Illuminator; he was followed to the grave in six months by his friend Mesrob. Moses of Khorene, bk. iii. cc. xlix.–lxviii., in Langlois, Hist. de l’Arménie, ii. 159–173; St. Martin, Mém. sur l’Arménie, i. 437; Galanus, Hist. Arm. c. vii.; Le Quien, Oriens Christ. i. 1375; Malan, Life of St. Gregory, p. 28.