Sima Lun
In 300, under the advice of a prince she favored—Sima Lun the Prince of Zhao, Emperor Wu's granduncle—Empress Jia decided to eliminate Crown Prince Yu as a threat. She sent assassins and had Crown Prince Yu assassinated. Sima Lun, however, had other plans—he wanted to have Empress Jia murder the crown prince so that he could use the murder as an excuse to overthrow her, and he started a coup later that year, killing Jia Mi, Zhang, Pei, and other associates of Empress Jia. Empress Jia was deposed and later forced to commit suicide. Sima Lun and his strategist Sun Xiu became the paramount authority.