In 900, Emperor Zhaozong was briefly forced by the eunuch Liu Jishu to abdicate in Li Yu's favor; after Emperor Zhaozong was restored, Li Yu was no longer Crown Prince but remained a favored son.
As Li Yu's brief reign was under duress from a eunuch, he is not typically considered a true emperor of Tang.
[6] After Emperor Zhaozong and his court were forced to flee from the imperial capital Chang'an to Hua Prefecture (華州, headquartered in modern Weinan, Shaanxi) after an attack by the warlord Li Maozhen the military governor (jiedushi) of Fengxiang Circuit (鳳翔, headquartered in modern Baoji, Shaanxi) in 896,[7] Emperor Zhaozong came under effective control of Han Jian the military governor of Zhenguo Circuit (鎮國, headquartered at Hua Prefecture).
(Subsequently, when Han ascertained that if he acted against the imperial princes that he arrested that he would not face retaliation from Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi), whom Emperor Zhaozong was still awaiting rescue from, Han slaughtered those imperial princes.
Late in 900, after an incident where Emperor Zhaozong personally killed a few eunuchs and ladies in waiting after being drunk, Liu acted.
[2] Less than two months later, a group of Shence officers loyal to Emperor Zhaozong (led by Sun Dezhao (孫德昭), Dong Yanbi (董彥弼), and Zhou Chenghui (周承誨)) killed Liu and Wang Zhongxian.
A group of eunuchs, in the disturbance, escorted Li Zhen to the Left Shence Army.
At the instigation of the chancellor Cui Yin, Zhu Quanzhong the military governor of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan) took an army to Fengxiang, put its capital Fengxiang Municipality under siege, and forced Li Maozhen to surrender the emperor to him.