Southern Mesopotamia was divided between competing city-states during the period 2900-2300 BCE. This so-called Early Dynastic period has three subdivisions based on archaeological finds made by the Oriental Institute of Chicago in the area of the Diyala, east of modern Baghdad. Early Dynastic I (around 2900-2800 BCE) saw the emergence of large independent cities such as Uruk. The cities were controlled by a king and his family, who owned vast estates.
Early Dynastic II (around 2800-2600 BCE) saw an increase in building and an improvement in the quality of artistic products like chlorite bowls, which also show connections with regions beyond Mesopotamia. The Early Dynastic II may be the period of rulers, like Gilgamesh, whose names survive in later legends.
The earliest writing is largely administrative, but by the beginning of Early Dynastic III (2600-2300 BCE) inscribed clay tablets contain many literary texts, including poetic hymns. Some of the best evidence for this period comes from the Royal Graves at Ur and the Dynasty of Lagash.