The monastery was founded by Samuel ( died in 409) and Mor Simon ( died in 433) in 397. Later, the monastery became so well knownthat its fame reached the Emperoros who werethen settled in Istanbul and Rome . Some of the buildings which were constructed with the contributions from the Roman Emperors such as Arcadius (395-450) and Anastasius (491-518) are still standing undamaged.
Besides its gorgeous and impressive features dating back to the 5th and 6th centuries such as the rare mosaics from Byzantine period, domes,cloisters,belfry,terraces,doors,motives, and decorations on the buildings carved in lime stone of Midyat, the monastery is one of the most important reliqious centers of the Sriac Church.
The Monastery of Mor Gabriel is at least 400 years older than any monastery which is built on famous Mount Athos in Greece and it is regarded as the "second Jerusalem" by the Syriac Church.The monastery was established 80 years before the Monastery of St. Saba in Palestine,and about half a century before the Monastery of St. Katerine in the Sinai region of Eygpt. So Mor Gabriel Monastery, which is one of the oldest and active Christian Monasteries in the world, is one of the very rare monasteries which managed to continue its monastic life style and traditions for 16 centuries.