What caused the demise of the Qin Dynasty?

First, the large-scale immigration policy; Second, Prince Chu Jun was not established too early, which led to his successor's lack of prestige, domestic troubles and foreign invasion, and no experience in handling government affairs.

The reasons for the demise of the Qin Empire are roughly as follows:

Immigration policy:

Over the years, the population and criminals have been migrating to the border and Guanzhong, resulting in changes in the population structure of Guanzhong: the old Qin people were evacuated and the original six countries occupied Guanzhong. The change of population structure made it impossible for the Qin Empire to effectively recruit soldiers and form elite soldiers to suppress the rebellion in the east.

The time of Qin Shihuang's migration was 1 and 2 19 BC, and 30,000 households (about15,000 people) moved to Langya, and 12 years, the relocated households were rewarded with exemption from corvee; 2. In 2 12 BC, 30,000 households (about15,000 people) moved to Lishan near Xianyang, and 50,000 households (about 250,000 people) moved to Zhangtai and Yunyang. In 10 year, the relocated households were rewarded to avoid corvee. 3. In 2 1 1 year BC, 30,000 households (about150,000 people) moved to the present Ordos area.

These are records of the migration of civilian population. In addition, when reunification was just completed in 2 17 BC,120,000 households (5 people in each household, with a population of 600,000), including the royal family and nobles, were forcibly moved to Xianyang.

The following are the records of migrant criminals. Although there are no exact figures, there are not a few: in BC 1 and BC14, criminals were sent to Yinshan, a newly conquered land of the Huns in Meng Tian, to enrich the newly established 34 counties; In addition, fugitives, slaves and shopkeepers were sent to Baiyue area in the South China Sea. 2. In 2 13 BC, corrupt officials were sent to repair the Great Wall or Baiyue area in the South China Sea; 3. In 2 12 AD, criminals were sent to the frontier again.

Just counting the migration records of civilians, there are already 6.5438+0.4 million households (about 700,000 people). 200,000 people must have moved to Guanzhong. These large-scale immigrants changed the foundation of the Qin people in Guanzhong, which made it impossible for the Qin empire to unite the people in Guanzhong as quickly as in the previous Warring States period and form combat effectiveness, thus resisting the invasion of the rebels. Liu bang easily entered Xianyang from Wuguan.