Uruk period
Sumerian cities during the Uruk period were probably theocratic and were most likely headed by a priest-king ("ensi"), assisted by a council of elders, including both men and women. It is quite possible that the later Sumerian pantheon was modeled upon this political structure. There was little evidence of organized warfare or professional soldiers during the Uruk period, and towns were generally unwalled. During this period Uruk became the most urbanized city in the world, surpassing for the first time 50,000 inhabitants.