Upper Mesopotamia Upper Mesopotamia Upper Mesopotamia is the name used for the uplands and great outwash plain of northwestern Iraq, northeastern Syria and southeastern Turkey, in the northern Middle East. After the Arab Islamic conquest of the mid-7th century AD the region has been known by the traditional Arabic name of al-Jazira ( "the island"), also transliterated "Djazirah", "Djezirah", "Jazirah" & the Syriac (Aramaic) variant "Gāzartā" or "Gozarto" (). The Euphrates and Tigris rivers transform Mesopotamia into almost an island, as they are joined together at the Shatt al-Arab in the Basra Governorate of Iraq, and their sources in eastern Turkey are
Mesopotamia (theme) Mesopotamia (theme) Mesopotamia () was the name of a Byzantine theme (a military-civilian province) located in what is today eastern Turkey. It should not be confused with the region of Mesopotamia or with the older Roman and early Byzantine province of Mesopotamia. The Byzantine theme was located between the rivers Arsanias (modern Murat) and Çimisgezek. The theme was formed probably between 899 and 911, when Emperor Leo VI the Wise (r. 886–912) appointed the former "strategos" of the Charsianon, named Orestes, as its governor. Most of the province was formed out the Armenian principality of Takis, ruled by the chieftain