In 649, Emperor Taizong died and was succeeded by his son
Li Zhi (as Emperor Gaozong). Cui Dunli continued to serve as minister of defense, and in 652, he commissioned Cui with an army to gather the remaining tribesmen of Xueyantuo to force them relocate to Qilian Prefecture (祁連州, a prefecture established for them in modern
Datong,
Shanxi). Later that year, Emperor Gaozong's sister
Princess Gaoyang, her husband Fang Yi'ai (房遺愛), Emperor Gaozong's uncle Li Yuanjing (李元景) the Prince of Jing, Emperor Gaozong's brother
Li Ke the Prince of Wu, another brother-in-law Chai Lingwu (柴令武), and the general Xue Wanche (薛萬徹), were implicated in a plot to overthrow Emperor Gaozong and replace him with Li Yuanjing. (According to traditional historians, Li Ke was not involved in the plot, but was falsely implicated by Emperor Gaozong's powerful uncle
Zhangsun Wuji, who was apprehensive that Li Ke was older and considered more capable than Emperor Gaozong.) Some of them were executed, and some were ordered to commit suicide. Emperor Gaozong initially wanted to spare Li Yuanjing and Li Ke, but at Cui's opposition did not do so. In 653, Cui was made
Shizhong (侍中)—the head of the examination bureau of government (門下省,
Menxia Sheng) and a post considered one for a
chancellor. He became in charge of editing imperial histories, and he was created the Duke of Gu'an. In 655, he was made
Zhongshu Ling (中書令), the head of the legislative bureau and still a chancellor post. In 656, Cui, who had been given an additional post as a staff member of Emperor Gaozong's son and crown prince
Li Hong as well, offered to resign on account of illness. Emperor Gaozong gave him the post as an advisor to Li Hong and no longer let him serve as
Zhongshu Ling, but gave him the designation of
Tong Zhongshu Menxia Sanpin (同中書門下三品), making him a chancellor
de facto. Emperor Gaozong also recalled Cui's younger brother Cui Yuqing (崔餘慶), who was then serving as the military advisor to the commandant at Dingxiang (定襄, in modern
Hohhot,
Inner Mongolia), from Dingxiang, to attend to Cui Dunli. Cui Dunli died less a month later. Emperor Gaozong personally led a public mourning and buried him with honors, near Emperor Taizong's tomb. == Notes and references ==