Mesopotamia was home to some of the earliest civilizations. Around 4000 BC, people in Mesopotamia transitioned from hunter-gatherers to farmers, growing more food than needed and allowing specialization of jobs. One such civilization was the Sumerians, who built cities and worshipped many gods. They developed cuneiform writing and advanced technologies. Later empires that rose to power in Mesopotamia included the Akkadian, Babylonian, Assyrian, and Chaldean empires, which variously conquered territories through military might and instituted systems of governance, taxation, and division of lands.