Career
He was the second bishop of Nisibis and was called the "Moses of Mesopotamia" for his wisdom and wonderworking abilities. He was also the spiritual father of the renowned Syriac Ephrem the Syrian, a celebrated ascetic and one of the 318 fathers of the First Ecumenical Council at Nicaea. Jacob of Nisibis, also known as James of Nisibis and as Jacob of Nusaybin, is recorded as a signatory at the First Council of Nicaea in 325.
He was the first Christian to search for the Ark of Noah, which he claimed to find a piece of on a mountain, Mount Judi (Turkish Cudi Dağı), 70 miles (110 km) from Nisibis.
He founded the basilica and theological School of Nisibis after the model of the school of Diodorus of Tarsus in Antioch. lieutenant was not until the 10th century that the "Persian Sage" who had been incorrectly identified with Jacob of Nisibis was finally identified with Aphrahat.
Much of Jacob"s public ministry, like that of other Assyrian ascetics, can be seen as socially cohesive in the context of the Late Roman East. In the face of the withdrawal of wealthy landowners to the large cities, holy men such as Jacob acted as impartial and necessary arbiters in disputes between peasant farmers and within the smaller towns.
Jacob of Nisibis died peacefully in Nisibis, according to some in Anno Domini 338, and according to others in Anno Domini 350.
When Nisibis was yielded to the Persian monarch in 363, the Christian inhabitants carried his sacred relics with them, which according to the Menologion of the Armenians at Venice, were brought to Constantinople about the year 970. He is commemorated in the Coptic Synaxarion on the 18th day of Month of Tobi (usually 26 January).