Li Chengqian
Yu Zhining (于志寧) (588–665), courtesy name Zhongmi (仲謐), formally Duke Ding of Yan (燕定公), was a chancellor of the Chinese Tang dynasty, during the reigns of Emperor Taizong and Emperor Gaozong. He had served on the staff of Emperor Taizong's oldest son and crown prince Li Chengqian and, after Li Chengqian was removed for plotting to overthrow Emperor Taizong in 643, received approval for having tried to correct Li Chengqian in his ways. Emperor Taizong promoted him, and he subsequently played prominent roles in the imperial government late in Emperor Taizong's reign and early in Emperor Gaozong's reign. In 659, however, because he had previously not supported the ascension of Emperor Gaozong's second wife Empress Wu (later known as Wu Zetian), he was removed from his office based on accusations by her ally Xu Jingzong that he had conspired with Emperor Gaozong's uncle Zhangsun Wuji, who had opposed Empress Wu's ascension.