The Sumerians were a presumably non-Semitic group of nomadic people, who may have come from the East (India or ancient Persia) and settled in Mesopotamia to establish one of the first major civilizations of the world, even before the ancient Egyptians. Although their exact arrival date is unknown, they seemed to exist in the area as a minor agricultural and organized civilization as early as the 5th millennium BC. Differing from previous city states, their country was the first large state formed by the aggregation and organization of several small cities.
The Sumerians are also credited with inventing the cuneiform writing system. Some of their major cities were Kish, Uruk and Ur. As the local Semitic tribes (Akkadians, Amorities and Elamites) grew in strength, the Sumerians began to lose their political hegemony over most parts of Mesopotamia and after a major blow from the Babylonians, they completely disappeared about the 2nd millennium BC.
The Sumerian religion has also been carefully studied and is thought to be the basis or source of inspiration for many religions since. The Sumerians believed in a polytheistic matriarchical cosmology, even though all historical records indicate that their society was male-dominated. See Sumerian Mythology.