Nabopolassar (/ˌnæbɵpəˈlæsər/; Akkadian: Nebû-apal-usur; c. 658 BC – 605 BC) was the king of Babylonia and played a key role in the demise of the Assyrian Empire following the death of the last powerful Assyrian king, Ashurbanipal. He ruled over Babylon for twenty years (625–605 BC).