司马伦
Yang Xianrong (羊獻容) (died 322), formally (as honored by Former Zhao) Empress Xianwen (獻文皇后, literally "the wise and civil empress") was an empress—uniquely in the history of China, for two different empires and two different emperors. Her first husband was Emperor Hui of Jin, and her second husband was Liu Yao of Han Zhao. Also unique was the fact that she was deposed four and restored four times as the empress of Jin (five, if one counts a brief usurpation by Sima Lun against her husband in 301).