When Nabopolassar of Babylon, the father of Nebuchadnezzar, rebelled against Assyria, Cyaxares the Mede allied his forces with the Babylonians. Following the Median capture of Asshur in Nabopolassar’s 12th year (634 B.C.E.), Cyaxares (called Ú-ma-kis-tar in the Babylonian records) met with Nabopolassar by the captured city, and they “made an entente cordiale.” (Assyrian and Babylonian Chronicles, by A. K. Grayson, 1975, p. 93)

With Babylonians defeat Assyria. After further battles against the Assyrians, finally in the 14th year of Nabopolassar (632 B.C.E.) the combined forces of the Medes and the Babylonians conquered Nineveh. (Zep 2:13) Assyrian resistance was transferred to Haran (some 360 km [225 mi]) to the W, but though Assyria received assistance from Egypt, the effort to continue Assyrian rule was ineffectual and the Assyrian Empire was split up between the Medes and the Babylonians. (Na 2:8-13; 3:18, 19) The Medes appear to have taken the northern portion of the territory while the Babylonians took the southern and southwestern portion, including Syria and Palestine.