Not much is known about the ancient Xia Empire of China. It probably lasted from 2205 - 1766 BCE.
This is the legend of its founding:
One day, a huge flood occured from the Yellow River. Many tribes stopped fighting and joined together to protect themselves and stop the floods. They were unsuccessful, and the Emperor called a man, Gun, to stop the floods. The floods only worsened- Gun failed. Then, his son, Yu the Great, tried. He ordered all tribes to build canals, so that the water would not go anywhere else. This worked; The Emperor Shun gave more power to Yu, and he defeated many wild nomads of China, therefore starting the Xia Dynasty.