司馬越
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. 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). 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.