The Qin Dynasty was the first unified absolutist centralized state in Chinese history. From 230 BC to 221 BC, Qin Shi Huang Yingzheng successively destroyed the six kingdoms of Kwantung and completed the unification of the country. He pioneered the emperor system, the central official system represented by the three princes and nine secretaries, and the county system, which completely broke the Shiqing Shilu system since the Western Zhou Dynasty, maintained the unity of the country, and strengthened the central government's control over the localities. It laid the foundation for the rule of the great unified dynasty in ancient China, so there is a saying that "a hundred generations are still Qin politics and law". But the tyranny of the Qin Dynasty also caused class contradictions and social unrest, leading to the first large-scale peasant uprising in Chinese history. In 206 BC, Prince Ying of Qin surrendered to Liu Bang. In just 15 years, the Qin Dynasty came to an end.
