Mesopotamia Egypt Indus Shang China Time period 3500 BCE 3200 BCE 2500 BCE 1650 BCE Geographic Description Tigris and Euphrates river flooding Few natural barriers Invasions and trade caused city-states to initially develop Nile River. Predictable floods. Natural barriers like desert. People settled on one side of river; other side reserved for religion; led to centralization Indus river and later Ganges Violent flooding due to seasonal monssons Buffered by the foothills of the Hindu Kush Mts although Arynas found a pass (Kyber Pass) Huang He (Yellow) and Yangtze rivers. Unpredictable flooding ?River of Sorrows? Natural barriers led to geographic isolation..Middle Kingdom. River meandered so it caused decentralized feudalism P Made organized city-states.