桓玄
In fall 403, Huan Xuan had Emperor An create him the Prince of Chu and give him the nine bestowments—both signs of an impending usurpation. In winter 403, Huan Xuan had Emperor An issue an edict (an edict that, according to traditional historians, Huan Xuan had Sima Bao () the Prince of Linchuan force Emperor An to personally write, although this account appears doubtful, as Emperor An's handicap makes it unlikely that he could personally write this edict) giving the throne to Huan Xuan. Huan then took the throne as emperor of a new Chu state. He created Emperor An as the Prince of Pinggu, but kept the emperor and his brother Sima Dewen the Prince of Langya (now reduced in rank to Duke of Shiyang) under virtual house arrest.