Mesopotamia (Gr. and , between the rivers, viz., Euphrates and Tigris; Heb. Aram Naharaim, Aram or Syria between the two rivers; now Al-Jeziveh, the island), an ancient country of western Asia, bounded, according to the common acceptation of the name, N. by Armenia, from which it was separated by the Masius range, a branch of the Taurus; N. E. and E. by the Tigris, separating it from Assyria; S. by Babylonia; and S. W. and W. by the Euphrates, separating it from Syria. The Greek name seems to have been first used in the time of the Seleucida). Mesopotamia has never been a political designation, but always a purely geographical one; and it is sometimes found applied also to the regions bordering on the valley of the two rivers. Excepting the Masius range and its prolongation parallel to the upper Tigris, Mesopotamia formed a vast and mostly very fertile plain, well watered by rivers and canals, the chief stream between the two great rivers being the Ohaboras, an affluent of the Euphrates, and the principal productions of the country grain, fruits, spices, timber, cattle, naphtha, and jet.
The southernmost part of the plain, however, resembled the adjoining regions of the Syro-Arabian desert, and was inhabited by numerous wild animals, including lions, ostriches, and wild asses. Among the cities of Mesopotamia were:
Apamea on the Euphrates, opposite Zeugma in Syria; Edessa (now Urfa), the capital of the province of Osroene; Carraj or Carrhffl, the llaran of Abraham; Circesium, the Scriptural Carchemish, near the mouth of the Chaboras; and Nisibis (Nizib), the Scriptural Zoba, in the province of Mygdonia. Mesopotamia was inhabited by a people called Rotennu or Reten-nu on the Egyptian monuments. They were of Semitic race, and were struggling with Egypt for supremacy as early as 1600 B. 0. In later times it was in turns a part of the Assyrian, Babylonian, Persian, Macedonian, Syrian, Parthian, and Neo-Persian monarchies, until it was conquered by the Arabs. It was subsequently invaded by the Seljuks, conquered in part by the crusaders, and finally became a province of the Ottoman empire.