China is a country with a long and rich history and ancient civilization. Chinese civilization began with the legendary sage-emperors Huang Di and Yan Di in the area of the Yellow River Basin. After centuries, the two tribes gradually merged into one by the time of the Xia Dynasty. Chinese people usually regard themselves as the descendants of Yan and Huang or call themselves Hua Xia People or Hua People. It was these people who established a state in the region of the Yellow River Basin – which was believed to be the center of the world, so the state was named “Middle Kingdom”. The history of China is generally told from the Xia Dynasty, which began in the 21st century B.C. and was followed by various dynasties until 1912 when Dr. Sun Yat-sen was proclaimed the provisional president of the Republic of China.