 The diocese is last mentioned in 1281, and probably lapsed in the fourteenth century during the disorders that attended the fragmentation of the Mongol empire.The East Syriac diocese of Armenia, whose bishops sat in the town of Halat on the northern shore of Lake Van, is attested between the fifth and fourteenth centuries.In the fifth century the diocese of Halat was not assigned to a metropolitan province, but was later included in the province of Nisibis, probably shortly after the Arab conquest of Persia.