Dayro d'Mor Sergius
This mnastery is thought to have been built in the fifth century in the name of the ascetics Sergius, Zura and Ba'uth, on the crest of the Qahil (Barren) Mountain between Balad and Sinjar, west of Mosul. It produced one Maphryono and some bishops and was a bishopric see from 1167 to 1345, after which it became deserted. Learning is presumed to have begun in it in the eighth century; however, it became famous in the ninth century.