The Incident at the Gaoping Tombs was a coup d'état that took place on 5 February 249 in the state of Cao Wei during the Three Kingdoms period (220–280) of China.
Cao Shuang surrendered and gave up his powers after further receiving reassurance that he and his family would be spared, thinking that he could still live a life in luxury.
He heeded the advice of He Yan, Deng Yang and Ding Mi (丁謐), and relocated Empress Dowager Guo (Cao Rui's widow) to Yongning Palace (永寧宮) so that she could not interfere in politics.
He also put his brothers in command of the military, promoted his close aides to higher positions in the imperial court, and made changes to the political structure to benefit himself and his clique.
At the time, there was a saying in Luoyang which went: "He (Yan), Deng (Yang) and Ding (Mi) create turmoil in the imperial capital.
"[3] In April or May 248, Zhang Dang (張當), a palace eunuch, illegally transferred 11 women out of the imperial harem and presented them to Cao Shuang to be his concubines.
[4] At the time, Li Sheng, one of Cao Shuang's supporters, had been recently reassigned to be the Inspector of Jing Province.
Sima Yi knew the true purpose of Li Sheng's visit, so he pretended to be frail and feeble.
Li Sheng returned to Cao Shuang and told him, "Sima Yi is dying soon and no longer of sound mind.
He went to Yongning Palace to meet Empress Dowager Guo and ask her to remove Cao Shuang and his brothers from power.
Yan Shi (嚴世), one of Cao Shuang's subordinates, prepared to fire an arrow at Sima Yi but his colleague Sun Qian (孫謙) stopped him and said, "We wouldn't know what will happen."
[7] Huan Fan, the Minister of Finance (大司農) and one of Cao Shuang's supporters, managed to escape from Luoyang and head to the Gaoping Tombs.
[8] Sima Yi then granted imperial authority to Gao Rou, the Minister over the Masses (司徒), appointed him as acting General-in-Chief (大將軍), ordered him to take command of Cao Shuang's troops.
Cao Shuang refused to listen to Huan Fan, and that night he sent Xu Yun (許允) and Chen Tai to meet Sima Yi.
[11] After returning to Luoyang, on 9 February 249[a] Cao Shuang was charged with plotting treason with the palace eunuch Zhang Dang (張當) and his associates He Yan, Ding Mi, Deng Yang, Bi Gui and Li Sheng.
Sima Yi had Wang Ling's co-conspirators, including Cao Biao, arrested and executed along with their families.
In the seventh installment of Koei's Dynasty Warriors video game series, a stage is dedicated to the initial coup d'état against Cao Shuang, while the other two are mentioned in the narration.