Emperor Wenzong had originally created his son Li Yong crown prince, but after Li Yong died in 838, he had been unsure whom to make his successor.

Emperor Wenzong's favorite concubine Consort Yang had recommended Li Rong, but when Emperor Wenzong consulted the chancellors, Li Jue had opposed this proposal.

Emperor Wenzong had thus, in 839, created Emperor Jingzong's youngest son Li Chengmei the Prince of Chen crown prince.

When Emperor Wenzong becomes seriously ill early in 840, he has his trusted eunuchs Liu Hongyi and Xue Jileng summon the chancellors Yang Sifu and Li Jue to the palace, intending to entrust Li Chengmei to them.

However, the powerful eunuchs Qiu Shiliang and Yu Hongzhi, who had not been not consulted in the decision, oppose Li Chengmei, and despite Li Jue's objection, forge an edict in Emperor Wenzong's name deposing Li Chengmei by claiming that Li Chengmei is too young, and creating Li Chan crown prince instead.

Subsequently, Qiu and Yu have soldiers escort Li Chan from his mansion to the palace and, after Emperor Wenzong then dies, persuade Li Chan to order Consort Yang, Li Chengmei, and Li Rong all to commit suicide.

After a short mourning period, Li Chan takes the throne as Emperor Wuzong.