In 829, Pei Du recommended Li Deyu, who was then the military governor of Zhenhai Circuit (鎮海, headquartered in modern Zhenjiang, Jiangsu) as chancellor, and Li Deyu was recalled from Zhenghai.
In 834, as Li Deyu had offended Emperor Wenzong's close associates Li Zhongyan and Zheng Zhu, as well as the powerful eunuch Wang Shoucheng (who had recommended Li Zhongyan and Zheng), Wang, Zheng, and Li Zhongyan wanted to find someone to counter Li Deyu.