1. Establishment and unification of the Qin Dynasty: The ancestor of the Qin Dynasty was Ying Zheng, the king of Qin who established the Qin Dynasty after unifying six countries. In this process, he carried out a series of reforms and measures, including carrying out legalist thought, centralizing power and strengthening army building.

2. The political and social system of the Qin Dynasty: The Qin Dynasty practiced strict centralization, including the emperor system, the three public officials and nine ministers system, and the county system. These systems effectively maintained the unity and stability of the Qin Dynasty, but they also brought a heavy burden to the people.

3. Economy and culture of Qin Dynasty: The Qin Dynasty carried out a series of economic reforms, including unified currency, weights and measures system and agricultural taxation. These reforms have promoted economic development, but they have also brought burdens to the people. At the same time, the Qin dynasty also carried out cultural reforms, including burning books to bury Confucianism and unifying writing. These reforms had a far-reaching impact on maintaining the unity and cultural inheritance of the Qin Dynasty.

4. The external expansion of the Qin Dynasty: After the unification of the six countries, the Qin Dynasty continued to expand its territory. One of the most famous is Qin Shihuang's expedition to the south and the Xiongnu. These wars not only expanded the territory of the Qin Dynasty, but also promoted national integration and cultural exchanges.

5. Decline and extinction of the Qin Dynasty: The late Qin Dynasty gradually declined, mainly due to political corruption, economic collapse and peasant uprising. In the end, the Qin Dynasty perished under the impact of the peasant uprising.

The name of the ruling dynasty

The title of Qin Dynasty comes from place names. According to Records of the Historian, the ancestors of the Qin Dynasty were sages Hao Tao and Boming (Boyi), and Fei Da, the ancestor of the Qin people, was a descendant of Zhuan Xu, the grandson of the Yellow Emperor, and was given the surname Won.

For me, Zhao Fu was a Zhou royal family, who put down Xu Qianli's rebellion and sealed it in Zhao Cheng. His clan is Zhao (in the pre-Qin era, "surname" was only the source, mostly used for offering sacrifices and addressing women, while "surname" was a branch of the family, addressing men), so "Zhao" was also one of the pronouns of Qin.

In the early Qin dynasty, people contributed to raising horses for the Zhou royal family, and were sealed in Qin by Zhou Wangxiao. During the ruling period, dogs invaded Haojing, which was officially made a vassal state because of its meritorious service in defending the Zhou royal family, and Qin became the national title. Before Qin Shihuang unified China, Qin was only a vassal state. After reunification, the name of a vassal state changed to that of a dynasty in China.