In 690, Empress Dowager Wu had Emperor Ruizong yield the throne to her, establishing a new Zhou Dynasty as Empress Regnant and interrupting Tang Dynasty. Emperor Ruizong was reduced to crown prince, while Li Chengqi was reduced to the title of "imperial grandson" (皇孫). For a while, Li Chengqi and his younger brothers were allowed to establish residences outside the palace, and Li Chengqi was given a staff. As Wu Zetian changed Li Dan's surname to Wu, Li Chengqi also carried the surname of Wu during Wu Zetian's reign.
