Sima Lun
Sima Ai was Emperor Wu's sixth son, born of the same mother as Sima Wei the Prince of Chu. He was granted the title Prince of Changsha in 289. When his father died in 290, Sima Ai was praised by many for his display of filial piety. When Sima Wei, at the command of Emperor Hui's wife Empress Jia Nanfeng, killed the regents Sima Liang the Prince of Ru'nan and Wei Guan, Sima Ai participated, and subsequently, when Empress Jia claimed that Sima Wei had forged the edict and executed him, Sima Ai was demoted to the lesser title of Prince of Changshan. Despite this, during the next few years, he received renown for his decisiveness, talents, and humility. When Sima Lun the Prince of Zhao usurped the throne in 301, Sima Ai was at his principality, and he led his own troops to join the forces of his brother Sima Ying the Prince of Chengdu against Sima Lun. Once Sima Ying and Sima Jiong the Prince of Qi were able to defeat and overthrow Sima Lun and restore Emperor Hui, Sima Ai, for his accomplishments, was restored to his original title as the Prince of Changsha.