Everyone knows that there was a Jin Dynasty in Chinese history, and it was also a unified dynasty. The Jin Dynasty was divided into two dynasties, the Western Jin Dynasty and the Eastern Jin Dynasty, which were also very wealthy at that time, including science and technology, culture and education, etc. were quite developed, but such a large dynasty only lasted for 152 years, of which the Western Jin Dynasty was 50 years and the Eastern Jin Dynasty was 102 years. The demise of the Jin Dynasty should have begun to decline after Sima Yan's death.
Sima Yan established the Jin Dynasty, only 24 years after his death, these 24 years are the most powerful and developed period of the Jin Dynasty, when there was also the only prosperous era of the Jin Dynasty in history, "Taikang Shengshi", but when Sima Yan died, the Jin Dynasty fell into civil unrest, and there was the Jia Nanfeng Rebellion, the Eight Kings Rebellion, and the Wuhu Chaohua Incident in history. Among them, the demise of the Western Jin Dynasty was only 26 years after Sima Yan's death, and the power of the Eastern Jin Dynasty at that time was in the hands of the scholars, the imperial power was extremely weakened, and the demise of the Eastern Jin Dynasty was only a time.
The reasons for the fall of the Jin Dynasty are mainly in the following three aspects:
1. The Sima family is not righteous in the country:
The founding of the Jin Dynasty was through improper and inferior means, killing political enemies indiscriminately, and forcibly seizing them, which can be said to have no bottom line for the sake of political power, and later even Sima Shao, a descendant of Sima Yi, was ashamed to say that when he heard about his ancestors' experience in gaining the country, he was ashamed to say, how can the country be maintained for a long time by obtaining political power by such means? It can be seen how despicable the Sima family's means were at that time, and even their descendants could not look at it, which was also a major reason for the eventual demise of the Jin Dynasty.
2. Implement the sub-sealing system:
In Chinese history, few unified dynasties have implemented a sub-feudal system, and since the establishment of the Qin state, they have all implemented a county system. Ancient China can be said to have experienced hundreds of years to abolish the sub-sealing system, but the Jin Dynasty fell well, and directly implemented the sub-sealing system from the beginning, not only did not innovate and progress, but also regressed. As the power of the princes became larger and larger, the imperial power became smaller and smaller, and finally those princes began to meddle in the government, which directly triggered the rebellion of the eight kings later, and the relatives of the Sima family killed each other, which really can be said to have wasted the vitality of the entire country of the Western Jin Dynasty. The Rebellion of the Eight Kings lasted for a total of 15 years, overdrawing the national strength of the entire Jin Dynasty, giving those ethnic minorities who entered the Central Plains a good opportunity to resist, and directly leaving no piece of armor for the Jin Dynasty.
3. The warrior clan seized the imperial power:
At that time, the warrior clan continued to rise and seized the imperial power. In the end, after Liu Yu was promoted to the throne, he cut the grass and roots of the Sima family, and the Sima family basically perished.
Summary: Although the Jin Dynasty was a unified country, it was criticized by later generations, the senses were very poor, and even infamous, because it was not orthodox and lacked faith, and I also felt that it was best to describe the Jin Dynasty with "born of injustice and died of injustice".