Sima Yue was the eldest son[3] of Sima Tai (司馬泰; posthumously known as Prince Wenxian of Gaomi (高密文献王)[4]), who was a son of Sima Yi's brother Sima Kui (司馬馗), making Yue a second cousin of Jin's founding emperor Emperor Wu. Sima Yue's mother was a grand-daughter of the Wei official Yang Jun (杨俊)[5]. In February 266, after Emperor Wu established the Jin dynasty, Sima Tai was named Prince of Longxi on 9 February.[6] As the eldest son, Yue's first title was "Heir to the Princedom of Longxi" (陇西世子). It was in this capacity that he was made a teacher who taught the classics to the crown prince Sima Zhong; other such teachers include Yang Miao (杨邈) and Sima Yao (司马繇), son of Sima Zhou.[7] His wife Lady Pei was a younger sister of Pei Dun, son of Pei Kang, elder brother of Pei Kai[8]; Pei Kang was an ancestor of the historians Pei Songzhi and Pei Ziye[9].
Sima Yue also took part in Jia Nanfeng's coup against Emperor Hui's first regent Yang Jun, and was made a marquis, with a fiefdom of 5000 households.[10] On 30 September 291,[11] he was created the Prince of Donghai. During the early parts of the War of the Eight Princes, he held a number of offices in the capital Luoyang.
In early 304, when the regent Sima Ai the Prince of Changsha (Emperor Hui's half-brother) was battling the forces of Sima Ying the Prince of Chengdu (also Emperor Hui's half-brother) and Sima Yong the Prince of Hejian (grandson of Emperor Hui's great-granduncle Sima Fu, Prince Xian of Anping [安平献王]), even though Sima Ai was fighting off the overwhelming force that Sima Ying and Sima Yong had, Sima Yue became convinced that a victory was impossible, and he seized Sima Ai and delivered him to Sima Yong's general Zhang Fang, who executed Sima Ai cruelly by burning him to death. Sima Ying controlled the government remotely, with Sima Yue being one of the generals who stayed in Luoyang to execute Sima Ying's orders.
As Sima Ying continued to remotely control the government from his stronghold of Yecheng (鄴城, in modern Handan, Hebei) as both regent and crown prince, the officials in Luoyang tired of the situation. Later in 304, Sima Yue led them in a rebellion against Sima Ying's forces, and he took Emperor Hui with him on the campaign. After some initial hesitation, Sima Ying fought and defeated Sima Yue's forces, forcing Sima Yue to flee. Emperor Hui was captured and taken to Yecheng. Subsequently, however, Sima Ying was defeated by Wang Jun, the commander of the forces of You Province (幽州, modern Beijing, Tianjin, and northern Hebei) and fled to Luoyang without his troops. Sima Yong then seized control of the government and Emperor Hui, deposing Sima Ying from his position as crown prince in February 305 and replacing him with another half-brother of Emperor Hui's, Sima Chi the Prince of Yuzhang. Later, Yong further had Zhang forcibly move Emperor Hui and Crown Prince Chi to Chang'an, under his firm control.[12]
Sima Yue decided to act against Sima Yong. In fall 305, he declared a rebellion with the stated intention of returning Emperor Hui to Luoyang. The warlords of the empire were forced to take sides, but eventually they generally fell into line behind Sima Yue because they were disgusted with Zhang's cruelty. The battles were initially largely indecisive, but early 306, after Sima Yue had some minor victories over Sima Yong's forces, Sima Yong panicked and killed Zhang, seeking peace with Sima Yue. Sima Yue refused, and by later that year was able to force Sima Yong to abandon both Emperor Hui and Chang'an. Sima Yue welcomed Emperor Hui back to the capital Luoyang. In January 307, Emperor Hui was poisoned to death, and historians generally agreed that the poisoning was done at Sima Yue's orders, but the motive was unclear. Crown Prince Chi ascended to the throne as Emperor Huai.
Emperor Huai, in contrast with the developmentally disabled Emperor Hui, was intelligent and astute, and he sought to revive the war-ravaged empire, but Sima Yue maintained a tight grip on authority and would not allow the emperor much actual power. On 18 May 307, he left Luoyang and set up headquarters at Xuchang (許昌, in modern Xuchang, Henan), but continued to control the government remotely. He also gave his younger brothers various titles and military appointments. Sima Teng, the second brother, was appointed Prince of Xincai, and was made Chief Controller of Si and Ji Provinces, while being garrisoned at Ye. Sima Lüe, the third brother, was made General who Attacks the South, Chief Controller of Jing Province and was garrisoned at Xiangyang. Sima Mo, the youngest brother, was appointed Grand General who Conquers the West and Chief Controller of Qin, Yong, Liáng and Yi provinces. He was garrisoned at Chang'an.[13] Later that year, on 25 August,[14] at the urging of his wife Princess Pei,[15] he issued an order that appeared insignificant at the time but would turn out to be important later on—making Sima Rui the Prince of Langye in charge of Yang Province (揚州, modern Zhejiang and southern Jiangsu and Anhui), at the post of Jianye (建業, in modern Nanjing, Jiangsu); this was the post from which Sima Rui would later, after the fall of Luoyang and Chang'an to Han-Zhao, claim the Jin imperial title[16].
In 309, Sima Yue, concerned about the growing use of authority that Emperor Huai was exerting, made a sudden return to Luoyang and arrested and executed a number of Emperor Huai's associates, including Emperor Huai's uncle Wang Yan (王延).[17] Other than privately mourning them, there was nothing that Emperor Huai could do. Sima Yue further disbanded the imperial guards and put his own personal forces in charge of protecting the emperor.
For all of Sima Yue's assertion of authority, he could not stop Han-Zhao, under its generals Liu Cong the Prince of Chu (the son of Han-Zhao's emperor Liu Yuan, Liu Yao the Prince of Shi'an (Liu Yuan's nephew), Wang Mi, and Shi Le, from disrupting Jin rule throughout northern and central China and gradually wearing out Jin forces and capturing Jin cities and towns. In late 309, he managed to fight off a joint attack by Liu Cong and Wang on Luoyang, but that victory was the exception to Han-Zhao's inexorable advances. After Liu Yuan died in 310 and was succeeded by Liu Cong, Han-Zhao renewed its attacks on the Luoyang region. Meanwhile, Sima Yue continued to alienate other generals and officials, and when Liu Kun, the military commander of Bing (并州, roughly modern Shanxi) proposed to him the plan of an attack on the Han-Zhao capital Pingyang (平陽, in modern Linfen, Shanxi) in conjunction with the powerful Xianbei chieftain Tuoba Yilu the Duke of Dai, Sima Yue was fearful of backstabbing attack by some of these warlords and therefore unable to accept Liu's plan. Indeed, when Emperor Huai and Sima Yue sent out calls for the various governors to come to Luoyang's aid later that year, there were few responses. Sima Yue became uncertain of himself, and late in 310 left Luoyang with virtually all of the central government's remaining troops, along with a large number of officials, effectively stripping Luoyang and Emperor Huai bare of their defenses, except for a small detachment commanded by Sima Yue's subordinate He Lun (何倫), intended as much to monitor as to protect Emperor Huai. From that point on, Luoyang was left even without a police force and became largely a city abandoned to bandits and thugs.
Emperor Huai soon entered into a plan with Gou Xi, the military commander of Qing Province (青州, modern central and eastern Shandong), who had been dissatisfied with Sima Yue, to overthrow Sima Yue's yoke. Sima Yue discovered this plan, but was unable to wage a campaign against Gou. He grew ill in his anger and distress, and died in April 311. The generals and officials in his army, instead of returning to Luoyang, headed east toward Sima Yue's principality of Donghai (roughly modern Linyi, Shandong) to bury him there. He Lun, upon hearing about Sima Yue's death, also withdrew from Luoyang and sought to join that force. However, both were intercepted by Shi Le and wiped out. Shi, declaring that Sima Yue had caused the empire much damage, burned Sima Yue's body. Sima Yue's sons were all captured and presumably killed by Shi. Only Princess Pei fled, and after much suffering, including a stint where she was enslaved, she arrived in Jianye during the Tai'xing era (318-321)[18]. Because she had persuaded Sima Yue to let Sima Rui have the Jianye post, Sima Rui was grateful to her and honored both her and Sima Yue posthumously, and allowed her to adopt his son Sima Chong (司馬沖; 311 - 28 August 341[19]) to serve as Sima Yue's heir.
As for his brothers-in-law (Princess Pei's brothers), Pei Dun was killed about a month after Sima Yue's death, when Xuzhou fell[20]. About a year earlier, Pei Chun[21], then Administrator of Xingyang, had fled to Jianye[22].
References
^Sima Yue's biography in Book of Jin noted that his first position was a teacher of the classics to Emperor Hui while the latter was crown prince (from early 267 to May 290). As such, his birth year should be c.260 or before.
^According to Sima Chi's biography in the Book of Jin, Sima Yue died on the bingzi day in the 3rd month of the 5th year of the Yongjia era of Emperor Huai's reign. This corresponds to 23 Apr 311 in the Julian calendar. [(永嘉五年三月)丙子，东海王越薨。] Jin Shu, vol. 05.
^While Sima Yue's biography in Book of Jin recorded that he was the second son (次子), Sima Tai's biography in the same work listed him as the eldest. As Yue was also heir to the Princedom of Longxi before he was made Prince of Donghai, it was more likely that he was the eldest son.
^Emperor Hui's biography in Book of Jin erroneously recorded Sima Tai's title as "Prince of Longxi" when he died in 299. It is unknown when exactly Tai's title was changed from "Prince of Longxi" to "Prince of Gaomi", but it should be between 296 and 299. After Sima Tai's death, his third son Sima Lüe was the next Prince of Gaomi.
^The Wei Jin Shiyu recorded that Yang Jun's grandson Yang Yi was a maternal uncle of Sima Yue. (《世语》曰：俊二孙：览字公质，汝阴太守；猗字公彦，尚书：晋东海王越舅也。) Shiyu annotation in Sanguozhi, vol.23. Yang Jun himself was on good terms with Sima Yi.
^(泰始元年冬十二月....丁卯，....封皇叔祖父孚为安平王，...泰为陇西王，....) Jin Shu, vol.03
^(初以世子为骑都尉，与驸马都尉杨邈及琅邪王伷子繇俱侍讲东宫，...) Jin Shu, vol.59. The "eastern palace" was a metonymy referring to the crown prince; Emperor Hui was crown prince from c.February 267 to May 290.
^(楷长兄黎，次兄康，并知名。康子盾，....。东海王越，盾妹夫也。) Jin Shu, vol.35.
^(裴子野字几原，河东闻喜人，晋太子左率康八世孙。兄黎，弟楷、绰，并有盛名，所谓“四裴”也。曾祖松之，宋太中大夫。) Liang Shu, vol.30. It is unknown which of Pei Kang's sons was Pei Songzhi's direct ancestor.
^(裴妃为人所略，卖于吴氏，太兴中，得渡江，....。) Jin Shu, vol.59. Emperor Yuan's biography in the same work recorded the era name as Da'xing (大兴).
^([咸康七年]秋八月辛酉，骠骑将军、东海王冲薨。) Jin Shu, vol.07; vol.96 of Zizhi Tongjian also recorded the same death date. (咸康七年薨，年三十一，...) Jin Shu, vol.64
^([永嘉五年]四月....贼王桑、冷道陷徐州，刺史裴盾遇害，...) Jin Shu, vol.05. The 4th month of the 5th year of the Yong'jia era corresponds to 5 May to 2 Jun 311 in the Julian calendar.
^Pei Chun being a son of Pei Kang was found in a Jin Zhugong Zan annotation in vol.23 of Sanguozhi. (<晋诸公赞>曰：康有弘量，....康子纯，黄门侍郎。次盾，徐州刺史。)
^([永嘉四年]五月，.....荥阳太守裴纯奔建邺。) Jin Shu, vol.05. The 5th month of the 4th year of the Yong'jia era corresponds to 14 Jun to 12 Jul 310 in the Julian calendar. Out of Pei Kang's sons, Pei Chun was the only one recorded to have successfully fled to the south. Thus, the unknown grandfather of Pei Mei (Pei Songzhi's grandfather) could be Pei Chun.
