Cao Fang
Although Cao Fang ruled for the longest period of time of all the rulers of Cao Wei, he was not in control of state power at any time during his reign. During his reign, the political scene was dominated by regents - Cao Shuang initially; then Sima Yi after he seized power from Cao Shuang during the Incident at Gaoping Tombs. After Sima Yi's death, Cao Fang attempted to take back state power from Sima Yi's son, Sima Shi, but was not successful and was eventually deposed by Sima Shi.