The most chaotic period in China's history was the Sixteen Countries Period in Wuhu, during which sixteen countries were established. Some countries have only existed for a few years and then collapsed directly. I think there are three main reasons for the collapse. First, the foundation is unstable, second, people's hearts are floating, and finally, all aspects have not developed.

1. Unstable foundation

During this period, the war on the land of China did not stop. Although there are only sixteen countries in Wuhu, these sixteen countries are quite representative. If you count the total, more than 20 regimes have been established. Although some regimes, such as the post-Zhao, the pre-Qin and so on, occupied a relatively large territory, and the pre-Qin also unified the whole country, the time was short and wars continued. Although some people are independent, their foundation is still intact.

2. People's hearts are floating

After so many years of war, the people have also suffered a lot. They fled everywhere, trying to find a place where there was no war to recuperate, but there was no way. Because of many factors, wars often occur, and they just want to find a country that is more suitable for them. After these wars, people's hearts are also floating, and there is no way to lay down the foundation of a place and build it well. Therefore, one person cannot be stable, and the whole country cannot be stable.

3. All aspects have not developed.

Because of the war, many countries have not developed in many aspects, such as economy. Some countries were good at first, but later their economies declined because of the profligacy of some descendants. Although some have laid a good foundation, they are not so good. Politically, their ruling style is not so advanced and backward, so the governance of the country is not very good. Finally, the Northern Wei Dynasty rose suddenly and successfully unified North China, and this period of history also entered the Southern and Northern Dynasties.