Isaac of Nineveh (d. c. 700) also remembered as Isaac the Syrian and Isaac Cyrus was a Nestorian bishop and theologian best remembered for his written work. He was born in the region of Qatar in the Persian Gulf. When still quite young, he and his brother entered a monastery, where he gained considerable renown as a teacher and came to the attention of the catholicos George, who ordained him bishop of Ninevah far to the north. The administrative duties did not suit his retiring and ascetic bent: he requested to abdicate after only five months, and went south to the wilderness of Mount Matout, a refuge for anchorites. There he lived in solitude for many years, eating only three loaves a week with some vegetables, uncooked, a detail that never failed to astonish his hagiographers. Eventually blindness and old age forced him to retire to the monastery of Shabar, where he died and was buried. At the time of his death he was nearly blind, a fact that some attribute to his devotion to study.
Isaac is remembered for his spiritual homilies on the inner life, which lend themselves to exerpting and have a human breadth that transcends his perhaps Nestorian Christianity. They survive in early Syriac and Arabic manuscripts and in Greek translations. From Greek they were translated into Russian.
Although ostensibly a Nestorian, Isaac’s writings were considered somewhat pro-Catholic, and thus many of his contemporaries questioned his commitment to Nestorian teachings.