Ur, located in southern Babylonia, was the site of the most ancient civilization in the world. Northern Mesopotamia was the center of the Assyrian Empire (1325 - 609 B.C.), and the Babylonian Empire (626 - 539 B.C.). At the end of the Babylonian era, Mesopotamia was conquered by the Persians and later by Alexander the Great. It was conquered briefly by Armenia during the Third Mithridatic War, but then came under the control of the Parthian Empire. Mesopotamia was conquered briefly by the Romans from 115 to 117 A.D.