司马亮
After Emperor Wu's death in 290, Yang Jun, the father of Empress Dowager Yang, assumed the regency for Sima Zhong, who ascended the throne as Emperor Hui. However, in 291, Yang Jun was overthrown and killed in a coup started by Empress Jia. Wei Guan was then made regent, along with Emperor Hui's granduncle Sima Liang. Wei Guan and Sima Liang tried to get the government on track, but Empress Jia continued to interfere with governmental matters. They also became concerned about the violent temper of Emperor Hui's brother Sima Wei (who was heavily involved in the coup against Yang Jun) and therefore tried to strip him of his military command, but Sima Wei persuaded Empress Jia to let him keep his military command. Sima Wei's assistants Qi Sheng () and Gongsun Hong () thereafter falsely told Empress Jia that Sima Liang and Wei Guan planned to depose the emperor. Empress Jia, who had already resented Wei Guan for having, during Emperor Wu's reign, suggested that he change his choice of heir apparent, also wanted more direct control over the government, and therefore resolved to undergo a second coup.