Even though Sumer was eventually able to over throw the Akkadians and rebuild Ur to a powerful city, it was never back to full strength. In time the powerful army of Babylon invaded and conquered Sumer. Babylon was once a Sumerian city-state but they became very strong and independent of Sumer. Babylon was located near where Baghdad Iraq is. The map on the right shows Babylon's empire in red at the height of it's power. Babylon had a powerful military leader named Hammurabi and he is a big part for their expansion and conquest.
