Sima Jun (; 232 – 2 November 286), courtesy name Zizang (子臧),(扶风武王骏，字子臧。) Jin Shu, vol.38 posthumously known as Prince Wu of Fufeng (扶风武王), was the youngest son of Sima Yi and his concubine Lady Fu, and a younger half-brother of Sima Shi and Sima Zhao. Sima Yi, Sima Shi and Sima Zhao eventually became regents of the Cao Wei state during the Three Kingdoms era. Besides his heritage, Sima Jun was best known for his involvement in the pacification of Tufa Shujineng's Rebellion during the reign of his nephew, Emperor Wu of Jin.

Life under Cao Wei Sima Jun was born in 232 during the reign of Cao Rui, as the youngest son of Sima Yi and his concubine Lady Fu; his elder full brothers were Sima Liang, Sima Zhou and Sima Jing (司馬京).(伏夫人生汝南文成王亮、琅邪武王伷、清惠亭侯京、扶风武王骏，...) Jin Shu, vol.38 A precocious child, Sima Jun could write court submissions and quote the classics fluently when he was four or five years old, surprising those who witnessed such acts.(幼聪惠，年五六岁能书疏，讽诵经籍，见者奇之。) Jin Shu, vol.38 When he was a bit older, he also had philosophical debates with Xun Yi on the Confucian values ren and xiao.(又與扶風王駿論仁孝孰先，見稱於世。) Jin Shu vol. 39 (biography of Xun Yi); before this anecdote, Xun Yi's biography recorded that he had become a tutor to Cao Fang. Note that at this point, Sima Jun had not yet received his title of Prince of Fufeng. Also, Xun Yi was more than 20 years older than Sima Jun.

In February 249, when Sima Jun was about 17 years old, his father, uncle, and eldest half-brother took part in a coup against the Cao Wei regent Cao Shuang; the success of the coup meant that from then on, the Sima clan was in control over Cao Wei, and this control increased further during Sima Shi's and Sima Zhao's tenures as regent.

Life during the Jin era In February 266, Sima Zhao's son Sima Yan accepted Cao Huan's abdication and founded the Jin dynasty. Sima Jun was then made Prince of Ruyin on 9 February, with a fiefdom of 10000 households.([泰始元年十二月]丁卯，...封皇叔祖父孚为安平王，...骏为汝阴王，...) Jin Shu, vol.03. (武帝践阼，进封汝阴王，邑万户...) Jin Shu, vol.38

In December 268 or January 269, Eastern Wu forces led by Ding Feng and Zhuge Jing attacked Hefei. As General Who Pacifies the East, Sima Jun was able to fend them off.([泰始四年]十一月，吴丁奉、诸葛靓出芍陂，攻合肥，安东将军汝阴王骏拒却之。) Zizhi Tongjian, vol.79. The month corresponds to 21 Dec 268 to 19 Jan 269 in the Julian calendar.

On 27 August 270,([泰始六年]秋七月...丁未，以汝阴王骏为镇西大将军、都督雍凉二州诸军事。) Jin Shu, vol.03 Sima Jun was appointed Grand General Who Guards The West and Chief Controller of Yong, Liang and the other western provinces, and he was tasked in protecting Guanzhong, replacing his elder brother Sima Liang.(遷鎮西大將軍、使持節、都督雍涼等州諸軍事，代汝南王亮鎮關中，加袞冕侍中之服。) Jin Shu, vol.38

After the initial failed attempts of the Jin court at quelling Tufa Shujineng's rebellion, Sima Jun focused his soldiers on agriculture in Guanzhong. In September or October 274, rebels from Liang attacked Jincheng again, but Sima Jun defeated them and killed one of their leaders, Qiwenni (乞文泥).([泰始十年]八月，涼州虜寇金城諸郡，鎮西將軍、汝陰王駿討之，斬其帥乞文泥等。) Jin Shu, vol.03. The month corresponds to 18 Sep to 17 Oct 274 in the Julian calendar. In 275, he campaigned against Shujineng and defeated his forces, killing 3,000 rebels.(咸甯初，羌虜樹機能等叛，遣眾討之，斬三千餘級。) Jin Shu, vol.38

Later that year, when Sima Jun was ordered to lead 7,000 soldiers to strengthen the garrison in Liang, Shujineng, Houdanbo (侯彈勃) and their followers planned to raid the military-agricultural colonies in Guanzhong in his absence. However, his subordinate, Wen Yang, led a combined force from Liang, Qin and Yong to threaten the rebels. Shujineng sent Houdanbo and twenty tribesmen to submit to Jin, each sending their sons as hostages. Wen Yang also received the surrender of 200,000 tribal people from Anding, Beidi and Jincheng including the chieftains Jikeluo (吉軻羅), Houjinduo (侯金多) and Rejiong (熱冏).([咸寧元年]二月...叛虜樹機能送質請降。) Jin Shu, vol.03. The 2nd month of the 1st year of the Xian'ning era corresponds to 14 Mar to 12 Apr 275 in the Julian calendar.(樹機能、侯彈勃等欲先劫佃兵，駿命平虜護軍文俶督涼、秦、雍諸軍各進屯以威之。機能乃遣所領二十部彈勃面縛軍門，各遣入質子。安定、北地、金城諸胡吉軻羅、侯金多及北虜熱冏等二十萬口又來降。) Jin Shu, vol.38 In June 276, Sima Jun campaigned against the northern "Hu" (北胡) and killed one of their leaders, Tudun (吐敦).([咸宁二年]夏五月，鎮西大將軍、汝陰王駿討北胡，斬其渠帥吐敦。) Jin Shu, vol.03. The month corresponds to 30 May to 28 Jun 276 in the Julian calendar. About six months later, in December, Sima Jun was promoted to Senior General Who Attacks the West.([咸寧二年]冬十月，以汝陰王駿爲征西大將軍...) Jin Shu, vol.03. The month corresponds to 23 Nov to 22 Dec 276 in the Julian calendar.

Death and aftermath In January 283, Sima You was ordered by Emperor Wu to leave Luoyang for his fiefdom of Qi. Sima Jun petitioned earnestly for Emperor Wu to rescind his order, but Emperor Wu refused. Sima Jun then fell ill, and after a long illness, he died in November 286.(及齐王攸出镇，骏表谏恳切，以帝不从，遂发病薨。) Jin Shu, vol.38. Sima You died in April 283, more than three years before Jun's death. After news of his death reached the western regions of the Jin empire, mourners filled the streets, and the locals erected steles for Sima Jun. Elders who saw the steles knelt to pay their respects.(西土闻其薨也，泣者盈路，百姓为之树碑，长老见碑无不下拜，其遗爱如此。) Jin Shu, vol.38 His son, Sima Chang (司馬暢; 270 - July 311) inherited his princely title; on 22 December 289,([太康十年十一月]甲申，...，徙扶風王暢爲順陽王，暢弟歆爲新野公，...) Jin Shu, vol.03; he was appointed Prince of Shunyang, while his younger brother Sima Xin was made Duke of Xinye. Sima Chang would later go missing during the Disaster of Yongjia; there were no further records of his activities or whereabouts.(永嘉末，刘聪入洛，不知所终。) Jin Shu, vol.38

Notes

References

Fang Xuanling, ed. (648). Book of Jin (Jin Shu). Sima Guang (1084). Zizhi Tongjian.