How did Sima Yi take over?
In March 230, Sima Yi was promoted to General-in-Chief (大將軍), appointed Grand Chief Controller (大都督), and given a ceremonial yellow axe. The Wei emperor, Cao Rui, put him and Cao Zhen in charge of defending Wei's western borders from attacks by its rival state Shu, which had been launching invasions since 228. At Cao ...
Is Cao Rui a good emperor?
As emperor. Cao Rui's reign was a paradoxical one in many ways. He was clearly intelligent and capable, and yet never fulfilled his potential in his governance of the country or in his military campaigns.