The Sima family, founded in the Western Jin Dynasty, perished so quickly. First, during the Western Jin Dynasty, the imperial clan was greatly enfeoffed, which limited the strength of counties and broke the balance of local forces and triggered the "Eight Kings Rebellion". Second, due to the continuous migration of a large number of Hu people, Hu people were recruited as soldiers in the war, which eventually led to the "five chaos." Third, because Sima Yan made Chu Jun and Sima Zhong weak, the imperial clan was in civil strife and internal friction was serious.
During the Western Jin Dynasty, the imperial clan was arbitrarily divided, the county army was restricted, and the imperial clan's rights were too large, which led to the "Eight Kings Rebellion". Sima Yan's success in overthrowing Cao Wei's rule was inseparable from the Jiupin Zheng Zhi system implemented at that time. Therefore, the Sima family won the support of the cremation and established the Jin Dynasty in one fell swoop. After the establishment of the Jin Dynasty, in order to prevent this from happening again, Sima Yan decided to restrict the rights of the gentry, wantonly appointed imperial clan and strengthened imperial power. Sima Yan first established dozens of royal families as kings, and they all had military power. Moreover, in order to further limit local power, the Jin Dynasty reduced the number of troops in counties, and the secretariat was deprived of the right to lead troops, which made the rights of local governors more and more powerful, and the power of counties was weak, thus triggering the "Eight Kings Rebellion".
A large number of Hu people continued to move inward and became soldiers in the Jin Dynasty, which eventually led to the scene of "five chaos".
At the beginning of the Western Jin Dynasty, civil wars continued, especially with the northwest ethnic minorities, so the soldiers and residents who surrendered by the northwest ethnic minorities moved to the Central Plains one after another. Moreover, in the Jin dynasty, this kind of Hu people's inward migration was very encouraged, but the large-scale inward migration broke the large proportion of Han people and foreigners in the north and did not disperse. Later, in order to supplement the troops, the Hu people were recruited into the army, and Liu Yuan, a Hun, served as the five governors during the reign of Emperor Jinhui. A large number of conference semifinals moved inward, which also led to the situation of "five chaos in China". In the end, the Huns attacked Chang 'an and destroyed the Western Jin Dynasty.
Sima Zhong, a Chu Jun founded by Sima Yan, was mentally weak and suffered from civil strife in the imperial clan of the Jin Dynasty, with serious internal friction. After Sima Yan acceded to the throne, he made Sima Zhong a prince according to the principle of "growing up by himself". However, with the growth of Sima Zhong, his weak intelligence has also been exposed. Although Sima Yan also had the idea of changing Chu Jun, he was stopped by the queen and princes, and finally Sima Zhong succeeded to the throne. After Sima Yan's death, the imperial clan has been in turmoil. After Emperor Sima Zhong destroyed the Queen Mother Yang's family, he abolished prisoners and killed the Prince. Sima Lun, the teacher of the prince, killed the queen for revenge and proclaimed himself emperor in 3 10. The civil strife of the Jin Dynasty royal family lasted for several years, with serious internal friction.
Therefore, there are many reasons for the short survival time of the Western Jin Dynasty. The Western Jin Dynasty wantonly enfeoffed clans, weakening the power of counties and counties, which led to the "Eight Kings Rebellion". The continuous migration of the Hu people also triggered the "Five Chaos". Not only that, there were many contradictions within the royal family, serious clan civil strife and serious internal friction, which led to the weakness of national strength, and finally failed to resist the Huns' attack, Chang' an was forced, and the Western Jin Dynasty eventually perished.