Sima Zhao

Sima Zhao (211 - 265), style name Zishang, was a military general, politician and regent of the state of Cao Wei during the Three Kingdoms period of Chinese history

He maintained control of Wei, seized by his father Sima Yi and maintained by his older brother Sima Shi, and had himself created the Duke of Jin — the penultimate step before usurpation of the throne, although he would never actually take the throne. He took advantage of weakness in Shu Han to the west and attacked it, forcing the surrender of Shu's people. His military credit helped to set up the plot of overthrowing Wei by his son, Sima Yan, who usurped the Wei throne and proclaimed the Jin Dynasty. After the establishment of Jin, Sima Yan posthumously honored his father as Emperor Wen of Jin (晉文帝), with the temple name of Taizu (太祖).

A Chinese idiom involving and inspired by Sima Zhao is one that states, "Everyone on the street knows what's in Sima Zhao's mind." (司馬昭之心, 路人皆知) meaning that a person's supposed hidden intention (in this case, usurping the throne) is so well known that it is not really hidden any more. It came from a quote by Cao Mao, fourth emperor of Wei, who launched an unsuccessful uprising against Sima Zhao to try to take back imperial power.