In 265 AD, Sima Yan overthrew Cao Empire and funded Jin Dynasty. The Western Jin Dynasty began. In 311 AD, Liu Cong led Hun, occupied Luoyang, the capital of Western Jin Dynasty, and captured Emperor Huai Di. The army of Western Jin supported Emperor Min Di to ascend the throne in Chang’an so as to continue the Western Jin regime. Five years later, which was in 316 AD, Liu Yao led his army to occupy Chang’an. Emperor Min Di gave it up and surrendered without resistance. That was the end of Western Jin Dynasty. In the second year Sima Rui ascended the throne in Jiankan City and reestablished the Dynasty of Jin known as East Jin.
West Jin Dynasty only extended for 52 years. But it gave an end to the disintegrated situation since the period of Three Kingdoms, and reunified China in 280 AD by Sima Yan. It created an opportunity for temporary social and economic development. West Jin Dynasty followed the system of Nine Grade Official Ranks from Cao Empire. But it had many disadvantages and soon was reduced to be a manipulation tool for power. After that the Menfa System came into being. Besides, West Jin Dynasty prescribed the franchise of bureaucratic nobles according to codes, and the franchise included the right of land-impropriation. Although Western Han Dynasty had been existed for 52 years, 16 years were in the turmoil of fights among eight leuds. It reflected the intense contradictions within the ruling empire.
West Jin Dynasty was quite advanced in social development. There were famous doctor Wang Shu and his great works Book of Pulse, geographer Pei Xiu and his Map of Yugong, and Chen Shou with the well-known historical book Annals of the Three Kingdoms.