Sumer, southern region of ancient Mesopotamia (presently southern Iraq). From c.3000 B.C.–2400 B.C. it was dominated by several small kingdoms, the first civilizations in the world. The kingdoms had developed from cities founded in the fertile valley between the Tigris and Euphrates rivers, a setting ideal for farming and raising cattle. The Sumerians created an advanced civilization, building palaces and temples and constructing irrigation canals in their fields. Their craftspeople were skilled weavers, potters, jewelers, and stonecarvers. Sumerians traded their goods with regions surrounding the Persian Gulf and promoted the practice and study of medicine, astronomy, mathematics, economy, law, and politics. One of their most noteworthy achievements was the development of the first writing system, known as cuneiform, consisting of wedge-shaped characters pressed into clay tablets. Other civilizations that took control of Sumer absorbed the knowledge and skills developed by them.
See also: Mesopotamia.