Cao Shuang and Sima Yi had shared power initially, but Cao Shuang had quickly employed a number of political maneuvers to honor Sima with honorific titles, including Grand Tutor, while stripping his actual power.

Cao Shuang then makes all important decisions and stops consulting Sima.

Quickly, Cao's associates, including Deng Yang, Li Sheng, He Yan, and Ding Mi, who are known for their talents but lack wisdom, all become powerful, and they exclude from positions of power other officials who will not associate with them.

Sima is still given military authority (including command in repelling a major Eastern Wu attack in 241), but no real authority on governance.