How did the physical features of Sumer contribute to isolated city-states? Explain your answer

Sumer is the South part of the ancient Mesopotamia. Sumerians are the people of Mesopotamia. People of Sumer segmented themselves into several city states which were self-reliant. Each state was situated near a Sumerian Temple.

Sumerian states often battled with each other to capture fertile lands and areas rich in water supply. Sumerian cities were fortified with thick walls to protect themselves from any foreign invasion.

Three class systems proved to exist, they were the poor, Middle class people were merchants and traders and Upper class who were King's families and priests. Most of the people in city states were poor farmers who were made to work on the Government land.