Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the Akkadian, Babylonian and Assyrian empires. In the Iron Age, it was ruled by the Neo-Assyrian and Neo-Babylonian empires. The indigenous Sumerians and Akkadians (including Assyrians & Babylonians) dominated Mesopotamia from the beginning of written history (c. 3100 BC) to the fall of Babylon in 539 BC, when it was conquered by the Achaemenid Empire. It fell to Alexander the Great in 332 BC and after his death it became part of the Greek Seleucid Empire.