to the favor that Wu Zetian had shown for them and that if they advocated Li Zhe's return and installation as crown prince, they would be able to maintain their power. The Zhangs agreed and advocated Li Zhe's return to Wu Zetian, who subsequently recalled Li Zhe from exile and made him crown prince. In 699, Zhang Yizhi was made the director of imperial attendants (控鶴監, Konghe Jian), overseeing a group of imperial attendants, including Zhang Changzong, Ji, Tian Guidao (田歸道), Li Jiongxiu, Xue Ji and Yuan Banqian (員半千). In 700, Zhang Yizhi was on one occasion offended by the official Yang Yuanxi (楊元禧)—a grandnephew of the Sui Dynasty chancellor Yang Su, who had been believed to be involved with Emperor Yang of Sui in killing Emperor Yang's father Emperor Wen of Sui. Zhang Yizhi retaliated against Yang Yuanxi by arguing to Wu Zetian that family members of Yang Su should not be allowed to serve in the capital, and Wu Zetian agreed, demoting Yang Yuanxi and his brother Yang Yuanheng (楊元亨) out of the capital Luoyang. Also in 700, in order to somewhat shield her relationship with the Zhangs from the public eye, Wu Zetian commissioned them and the imperial scholar Li Jiao to compile a work known as the Essence of Pearls from the Three Religions (三教珠英, Sanjiao Zhuying)—a compilation of various poetry about Confucianism, Buddhism, and Taoism—to give the Zhangs a legitimate reason to enter the palace. By 701, Wu Zetian, then 76 years old, had been largely entrusting the affairs of state to Zhang Yizhi and Zhang Changzong—a situation that her grandson Li Chongrun (son of Li Zhe, who had by now changed his name to Xian) disapproved and had discussed with his sister Li Xianhui the Lady Yongtai and Li Xianhui's husband, Wu Zetian's grandnephew Wu Yanji (武延基) the Prince of Wei. When the Zhangs became aware of the conversation, they reported this to Wu Zetian, who saw this discussion as an implicit criticism of herself, and she ordered Li Chongrun, Li Xianhui, and Wu Yanji to commit suicide. In 702, Wu Zetian induced Li Zhe, his younger brother Li Dan the Prince of Xiang, and Princess Taiping to submit formal petitions to create Zhang Changzong a prince. Wu Zetian formally rejected the petitions, but then created Zhang Changzong the Duke of Ye and Zhang Yizhi the Duke of Heng. By 703, the Zhangs were