Sumer

Sumer was the earliest known urban civilization, occupying southern Mesopotamia in what is now southern Iraq from roughly the fourth millennium BCE. Its city states, including Uruk, Ur, Eridu and Lagash, were governed independently, often at war with one another, and organized around temple complexes dedicated to local patron deities. Sumerians are credited with the invention of cuneiform writing, one of the earliest writing systems anywhere, initially used to record temple accounts and later extended to law, literature and royal inscriptions, including the Epic of Gilgamesh. Sumerian civilization also developed the wheel, the plow, systematic irrigation and some of the earliest law codes, and its religious and literary traditions strongly influenced the later civilizations of Babylon and Assyria that succeeded it in Mesopotamia.