linguistic:paraphrasing, structural:reformatting
Uruk period

In addition to being one of the first cities, Uruk was the main force of urbanization and state formation during the Uruk period, or 'Uruk expansion' (4000–3200 BC). This period of 800 years saw a shift from small, agricultural villages to a larger urban center with a full-time bureaucracy, military, and stratified society. Although other settlements coexisted with Uruk, they were generally about 10 hectares while Uruk was significantly larger and more complex. The Uruk period culture exported by Sumerian traders and colonists had an effect on all surrounding peoples, who gradually evolved their own comparable, competing economies and cultures. Ultimately, Uruk could not maintain long-distance control over colonies such as Tell Brak by military force.