Mor Gabriel Monastery (Deyrulumur Monastery) is located 23 kilometers southeast of Midyat district. The monastery is one of the famous and great monuments of the Syriac Ancient Community. It was built on a high hill covered with oak trees. The foundations of the monastery were laid by Mor Shmuel and Mor Shemun in 397 and the building was completed in a short time. Additions were made inside and outside at different dates.

In 615 and 1049, the monastery became a metropolitan center, and during the reign of King Arcadius (395-408), Mor Shemoun built places of shelter and prayer. During the reign of King Theodosius (408-450), the monument house for sarcophagi, the Church of the Virgin Mary, the Church of the Apostles, the Church of the Forty Martyrs, the Mor Shmuel Shrine, the Theodora Dome due to the healing of the king's daughter Theodora by Mor Shmuel, and the Mor Shlemun Shrine were built.

Mor Gabriel Monastery is at least 400 years older than any monastery on Mount Athos in Greece. It is about 80 years older than the Mor Saba Monastery in Palestine and a century and a half older than the Mort Katherina Monastery in Sinai, Egypt. 

The monastery has been known by different names from time to time in the historical process. In its early periods, it was known as Mor Şmuel and Mor Şemun Monastery, after the names of its founders. It is also known as Deyr-el Umur, which means "Abode of the Monks" and is derived from the Syriac name "Dayro d'Umro", and "Deyrulumur", a Turkish adaptation of this expression. Kartmin is also known as "Kartmin Monastery" due to its proximity to today's Yayvantepe Village. The name "Mor Gabriel Monastery", which is still used today, comes from the name of Mor Gabriel (634-668), Metropolitan of Turabdin.