Article: The earliest dynastic king on the Sumerian king list whose name is known from any other legendary source is Etana, 13th king of the first dynasty of Kish. The earliest king authenticated through archaeological evidence is Enmebaragesi of Kish (c. 26th century BC), whose name is also mentioned in the Gilgamesh epic—leading to the suggestion that Gilgamesh himself might have been a historical king of Uruk. As the Epic of Gilgamesh shows, this period was associated with increased war. Cities became walled, and increased in size as undefended villages in southern Mesopotamia disappeared. (Gilgamesh is credited with having built the walls of Uruk).

Question: What is the period of Enmebaragesi's reign associated with?
increased war