Southern mesopotamia in the first half of the 3rd millennium bc

We are talking about the causes of cities and villages in the period 3000 years BC. e. in the cities of Mesopotamia on the Sumerian lands. On the urban planning art of those times, the reason for the emergence of cities is the development of an economic basis - the transition to crafts and trade, and, as a whole, the society of the system, to a class society.