The chancellor Cui Yin, who harbors an ardent hatred for the eunuchs and who is allied with Zhu Quanzhong, is meanwhile also rising in power at the Tang court.

By 900, Emperor Zhaozong, who has come to trust Cui and who will later describe him as "faithful but trickier" (than Han Wo, the official to whom the emperor was addressing his comment) is planning with Cui to slaughter the eunuchs.

When Cui's fellow chancellor Wang Tuan urges against such action, believing the plans to be too drastic, Cui accuses Wang of being in league with the powerful eunuchs Zhu Daobi and Jing Wuxiu, who serve as the directors of palace communications.

Upon Cui's accusations, Emperor Zhaozong orders Wang, Zhu Daobi, and Jing to commit suicide, and it is said that from this point Cui became the leading figure at court, the eunuchs regarding him with anger and fear.

The eunuchs also have become fearful of Emperor Zhaozong himself, who, after returning from Hua Prefecture, is described to be depressed, alcoholic, and unpredictable in his temperament.

The four top-ranked eunuchs—Liu Jishu and Wang Zhongxian, the commanders of the Shence Armies, and Wang Yanfan and Xue Qiwo, the new directors of palace communications—begin plotting to remove him.

After an incident in winter 900 in which Emperor Zhaozong, in a drunken rage, kills several attending eunuchs and ladies in waiting, Liu Jishu leads Shence Army troops into the palace and forces Emperor Zhaozong to yield the throne to his son Li Yu the Crown Prince.

Emperor Zhaozong and his wife (Li Yu's mother) Empress He ware honored as retired emperor (Taishang Huang) and retired empress (Taishang Huanghou) but put under house arrest.

Li Yu, whose name the eunuchs change to Li Zhen, is proclaimed emperor, but the eunuchs control the court.

They want to kill Cui, but are fearful that Cui's ally Zhu Quanzhong might react violently, so they only relieve Cui from his secondary posts as the director of finances and the director of salt and iron monopolies.