As of Wu Zetian's
Tianshou era (690–692), Cui Yuanzong was serving as the minister of justice (,
Qiuguan Shangshu). In 692, Wu Zetian made him
Luantai Shilang (), the deputy head of the examination bureau of government (,
Luantai), and gave him the designation
Tong Fengge Luantai Pingzhangshi (), making him a
chancellor de facto. It was said that Cui was diligent while serving in office, and whenever he was on duty, he would stay late and take few breaks. He was also said to be careful in his actions and did not have any gourmet foods for over 20 years. However, he was also said to be, while appearing to be lenient on the outside, actually very harsh as a judge, and he picked faults with people and gave them heavy punishments, and therefore was feared. In 694, he was accused of crimes and exiled to Zhen Prefecture (, roughly modern
Sanya,
Hainan), and it was said that there was much rejoicing among other officials of his exile. At a later point, after a general pardon, he was recalled and served as imperial censor (,
Jiancha Yushi). == During Emperor Zhongzong's reign ==