司馬師
In 249, during the Incident at Gaoping Tombs, Sima Yi seized power from Cao Shuang in a "coup d'état" and had Cao Shuang's entire clan executed. Since then, the Wei government was effectively controlled by the Simas. After Sima Yi's death, the power was inherited by his eldest son Sima Shi, and was later passed on to his second son Sima Zhao when Sima Shi died.