Geography of Mesopotamia parts of Syria but also almost all of Iraq and southeastern Turkey. The neighboring steppes to the west of the Euphrates and the western part of the Zagros Mountains are also often included under the wider term Mesopotamia. A further distinction is usually made between Upper or Northern Mesopotamia and Lower or Southern Mesopotamia. Upper Mesopotamia, also known as the Jazirah, is the area between the Euphrates and the Tigris from their sources down to Baghdad. Lower Mesopotamia is the area from Baghdad to the Persian Gulf. In modern scientific usage, the term Mesopotamia often also has a chronological connotation.
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