The War of the Eight Princes, Rebellion of the Eight Kings, or Rebellion of the Eight Princes () was a series of coups and civil wars among kings/princes (Chinese: wáng 王) of the Chinese Western Jin dynasty from 291 to 306 AD. The period spanned the reign of Emperor Hui of Jin, whose powerful relatives fiercely contended with one another over his regency and succession in light of his developmental disability. The name of the conflict is derived from the biographies of the eight princes collected in Chapter 59 of the Book of Jin.
The "War of the Eight Princes" is somewhat of a misnomer: rather than one continuous conflict, the War of the Eight Princes saw intervals of peace interposed with short and intense periods of internecine conflict. At no point in the whole conflict were all of the eight princes on one side of the fighting (as opposed to, for example, the Rebellion of the Seven States). The initial conflicts prior to the coalition against Sima Lun in 301 were also not wars, but rather a series of political intrigues and coups d'état. The literal Chinese translation, Disorder of the Eight Kings, may be more appropriate in this regard.
While initial conflicts were relatively minor and confined to the imperial capital of Luoyang and its surroundings, the scope of the war expanded with each new prince who entered the struggle. The civil wars opened the empire to rebellions, most notably by tribal subjects that had resettled into the Central Plains. At its conclusion, the war devastated the Jin heartlands in northern China, and ushered in the Sixteen Kingdoms era in northern China, causing more than a century of warfare between the numerous short-lived dynasties in the north and the Eastern Jin dynasty in the south.
The Eight Princes The "Eight Princes" is a Tang-era retrospective grouping from the joint biography of eight Sima family royals who held control over the Jin imperial court during the reign of Emperor Hui of Jin. Their biographies jointly appear in Chapter 59 of the Book of Jin (compiled 648 AD). The following table lists them in rough chronological order by the date each first held effective power at the Luoyang court. Generational labels follow descent from Sima Yi (司馬懿, 179–251), the dynasty's posthumously-honoured founder.
+ The Eight Princes of the Jin civil war (291–306) Name (Pinyin) Chinese Born – Died Relation to Sima Yi Princely title Period of dominance at court Cause of death Notes Sima Liang 司馬亮 ? – 291 Son (4th surviving son, by Lady Fu) Prince of Ru'nan (汝南王) March – June 291 (c. 3 months) Killed at his residence by troops of Sima Wei acting on a forged edict procured by Empress Jia Nanfeng Senior surviving member of his generation. Named co-regent with Wei Guan after the overthrow of Yang Jun; his cautious, conciliatory style alienated both the empress and the younger princes. Sima Wei 司馬瑋 271 – 291 Great-Grandson (5th son of Emperor Wu Sima Yan) Prince of Chu (楚王) Effectively a single night in June 291 Beheaded in the Eastern Market of Luoyang the morning after killing Liang, after Empress Jia publicly disavowed the edict she had given him Hot-tempered and young (aged 20). His use as a cat's-paw and rapid disposal set the template for the next fifteen years of court politics. Sima Lun 司馬倫 ? – 301 Son (9th and youngest son, by Lady Bai) Prince of Zhao (趙王) Late 300 – May 301 (as regent then usurper) Forced to drink poisoned wine (gold-flake liquor, 金屑酒) after being deposed Only one of the eight to formally usurp the throne (proclaimed himself emperor in January 301, deposing Emperor Hui). His coup against Empress Jia in 300 is conventionally treated as the start of the war's open military phase. Dominated by his advisor Sun Xiu. Sima Jiong 司馬冏 ? – 302 Great-grandson (son of Sima You, who was Sima Zhao's son and Emperor Wu's brother) Prince of Qi (齊王) Late May 301 – January 303 (c. 18 months) Killed in street fighting at Luoyang by forces of Sima Ai; head displayed at the Eastern Gate Led the coalition that overthrew Sima Lun and restored Emperor Hui. As Grand Marshal (大司馬), ruled in the emperor's name from his own residence rather than the palace, which contemporaries cited as the cause of his fall. Sima Ai 司馬乂 277 – 304 Great-Grandson (6th son of Emperor Wu) Prince of Changsha (長沙王) January 303 – January 304 (c. 12 months) Roasted to death over a slow fire on the orders of Zhang Fang, Sima Yong's general The only one of the eight widely portrayed in the sources as competent and personally honourable. Held Luoyang against the combined armies of Ying and Yong for months before being betrayed from inside the city by Sima Yue. Sima Ying 司馬穎 279 – 306 Great-Grandson (16th son of Emperor Wu) Prince of Chengdu (成都王) 304 (designated Imperial Younger Brother [皇太弟] and heir) Strangled in prison in Ye by Liu Yu, an official under the Prince of Fanyang, Sima Xiao. Based at Ye, not Luoyang; preferred to govern from his base. Had the strongest military until defeat by Wang Jun (Sima Yue's ally) and quickly lost power. Was the only one among the eight princes to be designated Imperial Younger Brother and heir Sima Yong 司馬顒 ? – 306 (or early 307) Grand-nephew (grandson of Sima Fu, Sima Yi's younger brother) Prince of Hejian (河間王) 304 – 305 (jointly with Ying); Chang'an-based throughout Strangled in his carriage en route to Luoyang after being lured there with a promise of the office of Excellency over the Masses (司徒) Not descended from Sima Yi, but maneuvered opportunistically to gain control as the direct descendants of Sima Yi killed each other. His general Zhang Fang was the period's most feared field commander; controlling Guanzhong gave Yong a power base independent of the Luoyang court. Sima Yue 司馬越 ? – 311 Grand-nephew (grandson of Sima Kui, Sima Yi's younger brother) Prince of Donghai (東海王) 306 – 311 (c. 5 years; the longest tenure among the eight) Died of illness (sources say of anxiety) at Xiang while leading an army against Shi Le One of two non-direct descendants of Sima Yi among the eight princes. Seized Sima Ai in a palace coup. Then relied on the armies of his brothers Sima Teng, Sima Mo, Sima Lue and their allies to defeat Sima Ying, Sima Yong and their allies. Conventionally considered the last of the Eight Princes and nominal victor. Believed to have poisoned Emperor Hui in January 307 and enthroned Emperor Huai. His death and the destruction of his army by Shi Le in 311 opened the way for the Disaster of Yongjia and the fall of Luoyang.
Other people of note included Emperor Hui of Jin, Emperor Hui's first regent Yang Jun, Empress Dowager Yang, Empress Jia Nanfeng, and the senior minister Wei Guan. It is also important to note that the fiefdom titles of the princes do not reflect their base of operation. Although Sima Ying was the Prince of Chengdu, he mostly operated in Ye and was never near his fief,According to Emperor Hui's biography in Jin Shu and vol.83 of Zizhi Tongjian, Sima Ying was stationed at Ye in early 299. Jin rebel Li Xiong would later occupy Chengdu in late 304, and declare himself the Prince of Chengdu. while Sima Yong, the Prince of Hejian, mainly stayed around Chang'an. Only Sima Yue made use of his fief in Donghai as a base during the course of the conflict. The rest of the princes were in Luoyang at their respective height of power.
The conflict can be divided into two parts. The initial period (290–291) mainly concerns the power struggle between the Yang and Jia clans as they fought for control for Emperor Hui in the wake of his ascension. Sima Liang and Sima Wei were the only two of the Eight Princes involved, and fighting was only limited to coups in the capital, Luoyang. The later period (300–306) began following the fall of the Jia clan, who held power over the imperial court behind Emperor Hui for a decade before they were deposed by Sima Lun in 300. This period, particularly after Sima Lun's usurpation in February 301, escalated into a series of civil wars in northern China as Emperor Hui changed hands several times to the remaining six princes.
Family Tree
– Emperors; – The Eight Princes - - - - - = The dashed line denotes an adoption
Background
In early 249, Sima Yi, an official, general, and regent of the state of Cao Wei during the Three Kingdoms period, effectively seized control of Wei after instigating a successful coup against his co-regent, Cao Shuang. Sima Yi and two of his sons, Sima Shi and Sima Zhao, came to serve as the de facto rulers of Wei in succession, while the Wei emperors were reduced to puppet rulers. In February 266, Sima Zhao's eldest son, Sima Yan, also known as Emperor Wu of Jin, forced the Wei emperor Cao Huan to abdicate the throne and established the Jin dynasty.
The Sima clan sought to learn from the mistakes that led to the Cao Wei's downfall. The Wei regime had previously discouraged their princes from holding government and military offices, instead sending them away to live in their fiefs. Sima Yi, with the backing of the powerful gentry clans, was thus able to take control over the Wei government with minimal resistance. Identifying this issue, Sima Yan bolstered his family power by enfeoffing his uncles, cousins, and sons with their own private armies. As time passed, these princes and dukes were given administrative powers over their lands and were granted the power to levy taxes and employ central officials. Many were also entrusted with important military responsibilities and given the right to command troops outside of their fiefdoms. These members were assigned to guard key cities such as Chang'an, Ye and Xuchang, as well as the Jin capital, Luoyang.
Additionally, Emperor Wu's reign was troubled by a succession crisis as he and many other became aware that his heir Sima Zhong was developmentally disabled. A faction of ministers in court wanted Wu's younger brother, the abled Sima You, to replace him as the Crown Prince, but Wu was adamant in upholding the traditional succession law that the eldest living son should succeed, just as his father, Sima Zhao had done for him. Zhong was strongly backed by both the influential Yang and Jia clans, being the son of Wu's first empress, Yang Yan and husband of Jia Nanfeng. Another factor for choosing Zhong was that Wu saw great potential in his grandson, Sima Yu, should he succeed Zhong in the future. In the end, Sima You's exile and untimely death in 283 effectively secured Sima Zhong's inheritance to the throne.
By empowering the princes, Emperor Wu intended for them to act as a safeguard for his successors should the gentry clans overstep their power, especially considering Sima Zhong's disability. He had hoped that his family members, by virtue of their familial ties, would cooperate with each other to protect the interests of their dynasty. However, after Sima Zhong took the throne and became a mere figurehead, the princes later proved themselves self-serving and willing to undermine one another for real control over the empire.
The War of the Eight Princes coincided with the upheaval of the so-called "Five Barbarians"; non-Chinese groups that had been resettling into the Chinese interior as far back as the Eastern Han dynasty. Through their civil wars and mismanagement of the empire, the Jin lost support from both the Chinese peasantry and the non-Chinese tribes, pushing them to join rebel groups in different parts of China. In 304, refugees from the Guanzhong led by the Ba Di founded the Cheng-Han dynasty in Sichuan, while the Five Divisions, descendants of the Southern Xiongnu, founded the Han-Zhao dynasty in Shanxi, thus beginning the Sixteen Kingdoms period. The princes also empowered the Xianbei tribes by employing them as auxiliaries in the final years of the conflict. South in the Yangtze region also saw the major rebellions of Zhang Chang and Chen Min, but these were ultimately suppressed.
Prelude: Yang Jun (290-291)
Ascension of Emperor Hui