The War of the Eight Princes (八王之乱) broke out after the death of Sima Yan (Emperor Wu of Jin) in 290. His successor was weak; the imperial princes—many of them Sima Yan’s sons and relatives—held large fiefs and armies. They fought for control of the regency and the court. The conflict dragged on from 291 to 306, with shifting alliances and repeated fighting in and around Luoyang.
Consequences
The war exhausted the Jin state and devastated the north. It drew in Xiongnu and other non-Han forces and led to the loss of the Central Plain. The Jin court eventually fled south (317), and China entered the long period of division known as the Sixteen Kingdoms in the north and the Eastern Jin in the south. The War of the Eight Princes thus marks the immediate aftermath of the Three Kingdoms period and the beginning of a new era of upheaval.