Boasting a civilization of over 5000 years, China is one of the four ancient countries in the world. Since the Xia Empire was established in 21 BC, the society experienced the Shang Dynasty, the Western Dynasty, the Spring and Autumn Period, and the slave system. Starting from the period of the Warring States in 475 BC, the society developed from the Qin Dynasty, the Han Dynasty, the Three Kingdoms, the Jin Dynasty, the Northern and Southern Dynasties, the Sui Dynasty, the Tang Dynasty, the period of Five Dynasties and Ten States, the Song Dynasty, the Liao Dynasty, the Jin Dynasty, the Yuan Dynasty, the Ming Dynasty, and the Qing Dynasty. But from the Dynasties of Qin to Qing China remained in a feudal state. It was then reduced to be a semi-colonized and semi-feudal society after the Opium War in 1840, which was initiated by imperialist invaders. It was not until 1911 that the rule of the Qing Dynasty was overthrown by the Revolution of 1911 led by Sun Yet-sen. On October 1st, 1949, the Communist Party of China, with Mao Zedong as the Chairman, united the Chinese people and founded the People's Republic of China.