The fortress of Rhabdion was mentioned by the 6th-century Greek historian Procopius, while the 6th-century "Notitia Antiochena" and the work of the 7th-century Greek geographer George of Cyprus both attest that Turabdium was an episcopal see. The bishop of Turabdium's seat was probably the village of Hah, in which were, besides the functioning 6th-century monastery, several ruined churches including the cathedral. The Tur Abdin became part of the Rashidun Caliphate in 640, during the Muslim conquest of the Levant. The Syriac Orthodox communities flourished under early Islamic rule; nearly 30 structures are known to have been wholly built or rebuilt in the following 150 years, during which most of the villages' churches were built.