측천무후
However, Cen would soon offend Wu Zetian and her Wu clan members. There had been a movement started by the official Zhang Jiafu and the commoner Wang Qingzhi (王慶之) to have Wu Zetian's nephew Wu Chengsi made crown prince—under the theory that given that Wu Zetian was now emperor, she should be succeeded by a member of the Wu clan rather than her husband's Li clan. They circulated a petition among officials, and Cen refused to sign—and further suggested to Wu Zetian that, as Wu Dan was already crown prince, this proposal should be firmly rejected and that the group of people that Zhang and Wang had gathered before the palace to petition Wu Zetian should be disbanded. He was supported in this by fellow chancellor Ge Fuyuan. Cen and Ge's actions offended both Wu Zetian and her Wu clan members.