Maʿsarteh was part of the Syriac Orthodox diocese of Dayro d-Mor Abay until the death of its last bishop Isḥoq Ṣaliba in 1730, upon which the diocese was subsumed into the diocese of Mardin.[11] German orientalist Eduard Sachau visited the village in 1880.[12] Maʿsarteh was inhabited by 300 Syriac Orthodox Assyrians in 1914 and served by the church of Mar Gewergis, according to the list presented to the Paris Peace Conference by the Assyro-Chaldean delegation.[13] Amidst the Sayfo, in 1915, the village's owner Huseyin Bakkero murdered 80 Assyrians at his house after assuring them of their safety and threw their bodies into wells.[14] Two men survived by hiding in a cave whilst one man fled to the Mor Hananyo Monastery and the women and children were hidden by some Kurdish women for a few days and then escorted to the Church of the Martyrs at Mardin.[15]
After the Assyrian genocide, Assyrians from Maʿsarteh emigrated to Bethlehem and Jerusalem.[16] In 1960, Maʿsarteh was officially renamed Ömerli.[17] By 1989, all Assyrian families had fled the town,[18] however, some later returned and, as of 2013, three Assyrian families inhabit the town.[19] The church of Mar Gewergis was converted into a mosque.[12]
Presently, the town mostly consist of Kurds and Mhallami.[20][21] Of the two groups, the first ones to settle in the town were the Mhallamis who came from villages between Ömerli and Midyat such as Şenköy and Çavuşlu, while Kurds from the Bilikan tribe supposedly settled in the town due to blood feud. The Bilikan Kurds would become Arabophone over time and came to dominate local politics because of the size of their large families. They are plausibly the largest group in the town.[21]
Other groups in the town include Kurds from other tribes, Arabs, few Assyrians and Georgians, and civil servants of Turkish roots.[21]
According to the leaders of the Kurdish Omerkan (or Omeryan) tribe, who lives in the vicinity of the town, Ömerli had been under their rule for many years and considered the town to be in their territory. However, the town is not affiliated with any Kurdish tribe.[2]
Bcheiry, Iskandar (2010). Collection of Historical Documents in Relation with the Syriac Orthodox Community in the Late Period of the Ottoman Empire. Gorgias Press.
Brock, Sebastian (2017). "A Historical Note of October 1915 Written in Dayro D-Zafaran (Deyrulzafaran)". In David Gaunt; Naures Atto; Soner O. Barthoma (eds.). Let Them Not Return: Sayfo – The Genocide against the Assyrian, Syriac and Chaldean Christians in the Ottoman Empire. pp. 148–157.
Shahîd, Irfan (1995). Byzantium and the Arabs in the Sixth Century, vol. 1, part 1: Political and Military History. Dumbarton Oaks.
Tan, Altan (2018). Turabidin'den Berriye'ye. Aşiretler - Dinler - Diller - Kültürler (in Turkish). Pak Ajans Yayincilik Turizm Ve Diş Ticaret Limited şirketi. p. 289. ISBN9789944360944.