Mesopotamia (theme)

Theme of Mesopotamia Μεσοποταμία, θέμα Μεσοποταμίας
Theme of the Byzantine Empire
899/900s–1070s
The Asian themes of the Byzantine Empire c. 950.
Historical era		Middle Ages
•	Established	899–911
•	Fall to the Seljuks.	1070s
Today part of		Turkey

Mesopotamia (Greek: Μεσοποταμία) 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 Manuel. Manuel and his four sons were persuaded to cede their territory to the Byzantine Empire in exchange for titles and estates in other themes. The Armenian-populated districts of Keltzene (detached from the theme of Chaldia) and Kamacha (part of the Theme of Koloneia) were then joined to it to form the new theme.

Although Emperor Constantine VII Porphyrogennetos (r. 913–959) mentions that before its elevation to a theme, the region was an "unnamed kleisoura", there is evidence, however, of much earlier Byzantine presence. A seal of a "spatharios and strategos of Mesopotamia" has been dated to c. 810, perhaps indicating the existence of a first short-lived theme there, and a seal of a tourmarches with the Armenian name Mousilikes, is tentatively dated to c. 870.

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