The city of Babylon is mentioned in documents of the late third millennium BC and became the centre of an Amorite dynasty in the early second millennium BC. The sixth Amorite ruler, Hammurapi, created an empire across Mesopotamia. It was the royal city of the Kassites and during the Second Dynasty of Isin (1157-1026 BC) it became the capital of southern Mesopotamia and its patron deity Marduk became the national god.
Nebuchadnezzar II rebuilt Babylon in the sixth century BC and it became the largest ancient settlement in Mesopotamia. There were two sets of fortified walls and massive palaces and religious buildings, including the central ziggurat tower. Nebuchadnezzar is also credited with the construction of the famous 'Hanging Gardens'.
Babylon remained an important centre until the third century BC, when Seleucia-on-the-Tigris was founded about ninety kilometres to the north-east. Under Antiochus I (281-261 BC) the new settlement became the official Royal City and the civilian population was ordered to move there. Nonetheless a village existed on the old city site until the eleventh century AD. Babylon was excavated by Robert Koldeway between 1899 and 1917 on behalf of the Deutsche Orient-Gesellschaft. Since 1958 the Iraq Directorate-General of Antiquities has carried out further investigations. Unfortunately, the earlier levels are inaccessible beneath the high water table.