司馬遹
Wang Dun was the son of the Jin official Wang Ji (王基), and he married Emperor Wu of Jin's daughter Princess Xiangcheng. He served as an assistant to Emperor Hui's crown prince Sima Yu, and when Sima Yu was falsely accused of crime by Empress Jia Nanfeng and deposed, he risked his life to attend the crown prince's farewell, and received renown from that. He later served as the governor of Yang Province (揚州, modern Zhejiang and southern part of Jiangsu and Anhui). After Sima Rui, then the Prince of Langye, became in charge of the military operations in the area in 307, both Wang Dun and his cousin Wang Dao became key assistants to him, and it was said at the time that the domain was ruled equally by the Simas and the Wangs.