High Level Overview of Chinese History: Western Jin
By Ian Kiu - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3708103
Founded by Sima Yan forcing Cao Huan to abdicate, the Western Jin began on 4 February 266. Cao Huan was demoted to Prince of Chenliu and later buried with imperial honors. Known as Emperor Wu of Jin, meaning the 'Martial Emperor of Jin', after his death, he would move to reunify China, a task he'd accomplish by 280. After this, China experienced a decade of peace under his rule, with economic prosperity as reflected by the 'extravagant and outlandish lifestyles of the aristocracy'. He decreed that his eldest son, Sima Zhong, who might have had a developmental disability, should follow him, per Confucian primogeniture.
During this time, several officials expressed concern over the population increase in the populations of non-Han people who had been living within China for centuries, many since the late Han dynasty. These groups had lived among the northern Han Chinese, picking up settled agriculture and were Sinicized to various degrees. Collectively, these groups were known as the Five Barbarians (Wu Hu) and consisted of the Xiongnu, Jie, Xianbei, Di, and Qiang. The Xiongnu were from the steppes of East Asia and despite no longer being unified, still drew a sense of identity from their shared ancestors. The Jie were primarily from the area around the Bing Province and had a relatively small population. The Xianbei occupied the Mongolian plateau and had become vassals in 207, though some moved to the Hexi Corridor. The Di were from northern and western China, though Cao Cao had 50,000 of them relocated toward central China to keep them from allying themselves to the Shu and as a result of their frequent rebellions, which continued under the Jin. The Qiang were a group from Qinghai and Gansu that had settled in Guanzhong where the watersheds of the Wei and Jing rivers were and often fought amongst themselves since they weren't a unified group as well as rebelling because of their poor treatment by the Han Chinese rulers.
When Emperor Wu died in 290, Emperor Hui, his son Sima Zhong, ascended and almost immediately, the War of the Eight Princes broke out, though this wasn't a single conflict, but rather a series of short, intense periods of conflict with intervals of peace, nor were all eight of the princes involved at the same time. The eight were members of the Sima family, most direct descendants of Sima Yi with two being grandnephews and three being sons of Emperor Wu. Emperor Wu considered having his father-in-law, Yang Jun, and his uncle, Sima Liang, as regents for Emperor Hui, but Yang Jun took advantage of Emperor Wu's failing health to sent Sima Liang away. He also hid the decree making him and Sima Liang co-regents and had his daughter, Empress Yang Zhi name him sole regent. Emperor Wu was too ill to stop this manipulation before he died.
Because Yang Jun was obviously trying to consolidate power, continued to try to assassinate Sima Liang, and refused to accept advice, the ministers were unhappy with him. Empress Jia Nanfeng was also unhappy that her power as Empress was being taken by the Empress Dowager Yang Zhi. Empress Jia called for Sima Liang and Sima Wei to overthrow Yang Jun. Sima Liang was reluctant, but Sima Wei started his troops marching on Louyang. On the 23 April 291, Empress Jia called for Yang Jun's deposal while her allies and army occupied the gates of his home. Yang Jun was caught flat-footed but Empress Yan Jia tried to get the troops to turn against Empress Jia, which implicated her in her father's plans. His family and supporters were 'executed as the extermination of all third degree relatives', the 'most severe punishment for a capital offense', except for Yang Zhi, who was confined in the palace for the rest of her life.
On 4 May 291, Sima Liang and Wei Guan became Emperor Hui's new regents. Sima Liang took advantage of his new position and handed out appointments and titles to about 1,081 people to gain their favor. Empress Jia also began placing her own relatives in positions of power at the same time. Sima Liang and Wei Guan were both concerned about Sima Wei, Emperor Hui's half-brother, who was 'notorious for his violent temperament', so they tried to strip him of his military power and make him return to his fiefdom, but he worked with Empress Jia to depose them. The edict that Empress Jia gave, however, didn't allow Liang Wei to raise his own military force, so he forged one that made him Commander of all military forces with full control over operations. He arrested Sima Liang and Wei Guan on 26 July 291 and they were both put to death.
After taking control of a significant part of the military through the forged edict, Sima Wei was advised to go after Empress Jia's relatives, Jia Mi and Guo Zhang, but he hesitated. Empress Jia was advised to punish Sima Wei for killing Sima Liang and Wei Guan. Empress Jia didn't hesitate and her troops against Sima Wei the next day, spreading that the edict wasn't authentic. Sima Wei was captured and executed and his full brother Sima Ai was demoted for supporting him.
This left Empress Jia as the defacto power in China for the next 9 years, with her relatives, especially Jia Mi and Guo Zhang, assisting her. Ministers like Zhang Hua and Pei Wei tried to keep the government running, but the widespread corruption of the Jia clan made it difficult. Rumors abounded that Empress Jia was particularly debauched and tyrannical, which laid the groundwork for the discontent that would grow through the decade. She also made a series of transfers that had an effect on the next stages of the War of the Eight Princes, such as moving Emperor Hui's great-uncle Sima Lun to Louyang after he failed to quell an uprising in 296 resulting from famine and plagues, and assigning Sima Ying, another half-brother of Emperor Hui, to Ye, near modern day Hebei, as the result of an argument he had with Jia Mi about how Sima Yu, the Crown Prince, was treated. The later required that Sima Yong, the Emperor Wu's second cousin and grandson of Sima Fu, was moved from Ye to Guanzhong, near central Shaanxi.
Sima Lun wormed his way into Empress Jia's inner circle and was a tutor to Sima Yu, the Crown Prince, even though he'd developed a reputation for being 'avaricious and false' as well as 'simple and stupid' and only listening to Sun Xiu, his personal confidant. Despite this reputation, he had command of some troops and was general of the Right Army Since the Crown Prince wasn't her son, Empress Jia didn't trust him and orchestrated having him copy a text while he was drunk that said the emperor should abdicate. Sima Lun saw the arrest as the opportunity he'd been waiting for. He and Sun Xiu spread rumors that there was a plot to restore Sima Yu to Crown Prince status, so they convinced Empress Jia to have him assassinated. On 7 May 300, after Sima Yu had been killed, Sima Lun produced a forged edict that removed Empress Jia as empress. She was arrested and put under house arrest before being forced to commit suicide. Many of her relatives and other appointees were executed, including Jia Mi, Zhang Hua, and Pei Wei.














