Background
Both Sima Mo and Sima Yue were sons of Sima Tai (司馬泰) the Prince of Gaomi, the son of Sima Yi"s brother Sima Kui (司馬馗). At the time of his father"s death, Sima Bao was at Shanggui (上邽, in modern Tianshui, Gansu).
司馬保景度元王
Both Sima Mo and Sima Yue were sons of Sima Tai (司馬泰) the Prince of Gaomi, the son of Sima Yi"s brother Sima Kui (司馬馗). At the time of his father"s death, Sima Bao was at Shanggui (上邽, in modern Tianshui, Gansu).
Sima Bao"s father Sima Mo (司馬模) the Prince of Nanyang was a younger brother of Sima Yue the Prince of Donghai, who was regent for Emperor Hui and Emperor Huai. He took the title of the Prince of Nanyang, and soon became in control of Qin Province (秦州, modern eastern Gansu). He was known for his generosity and openness, and the people of the province, whether Han, Di, or Qiang, were said to be open to his leadership.
He was also grossly overweight—according to historians, at 800 Chinese pounds (jin, 斤) -- or roughly 400 kilograms (880 pounds) and said to be impotent, and therefore had no children.
He entered into an alliance with Zhang Gui (張軌), the governor of Liang Province (涼州, modern central and western Gansu), and Zhang"s domain, largely untouched by wars, often supplied Sima Bao"son After Emperor Minister assumed the throne in 313, Sima Bao, whose troops were still sizable, was given the title of right prime minister (右丞相), but while he took occasional campaigns to relieve Emperor Minister"s government, then at Chang"an, from pressures being applied by Han Zhao forces, he took no actual actions to put Emperor Minister under his protection.
Indeed, in 316, when his generals briefly defeated Han Zhao forces seeking to siege Chang"an, they stopped short of reaching Chang"an, which was then captured by Han Zhao forces, causing Emperor Minister to be captured. Sima Bao then considered taking the emperor title for himself.
In 319, he took a title one stop from that—by declaring himself the Prince of Jin, the same title that the founding emperor Emperor Wu"s father Sima Zhao took during his stint as Cao Wei"s regent.
He believed that Zhang Gui"s son and successor Zhang Shi (張寔) would support him, but Zhang decided not to commit, believing that Sima Rui the Prince of Langye, who had claimed the imperial title in 318 after Emperor Minister was executed by Han Zhao, might be the more appropriate emperor. In early 320, when the Han Zhao emperor Liu Yao decided to undertake a major campaign to wipe out Sima Bao, Sima Bao"s domain happened to be suffering under a famine, and he fled to Sangcheng (桑城, in modern Dingxi, Gansu), ready to flee to Zhang"s domain. Zhang sent a force that ostensibly was to protect Sima Bao, but instead was intended to stop him from arriving in Zhang"s domain.
Sima Bao did not agree with them.
Soon, he died—with some historians believing that he was murdered by Zhang and Yang Ci, while some historians believed he died of natural causes. Zhang and Yang Ci, because Sima Bao was sonless, supported a son of the Sima clan, Sima Zhan (司馬瞻) to be Sima Bao"s heir.
Chen, still bearing some loyalty to Sima Bao and believing that he had been murdered, attacked and killed Sima Zhan. Zhang fled, but Yang Ci was captured, and Chen executed him before Sima Bao"s casket, and then buried Sima Bao with honors due an emperor and gave him the posthumous name of Prince Yuan.
Late in 313, after Emperor Huai was captured by Han Zhao after the fall of the capital Luoyang, Sima Mo, who was defending Chang"an, was captured by the Han Zhao general Zhao Ran (趙染) and executed.
