[3] However, the main sources on his rise — the New Book of Tang and the Zizhi Tongjian — disagree with each other (and somewhat internally) as to his career progression and actions.
Emperor Zhaozong was then at Hua Prefecture after fleeing the imperial capital Chang'an with his court after coming under attack by the warlord Li Maozhen the military governor of Fengxiang Circuit (鳳翔, headquartered in modern Baoji, Shaanxi).
[5] According to the New Book of Tang, however, it appeared that Liu was director of palace communications when Emperor Zhaozong, at the instigation of the chancellor Cui Yin, killed the commanders of the Shence Armies Zhu Daobi (朱道弼) and Jing Wuxiu (景務脩) in 900 and replaced them with Liu and Wang Zhongxian (王仲先) — whereas the Zizhi Tongjian referred to Zhu and Jing, at their deaths, as directors of palace communications.
Liu drafted a petition that he then forced Cui and other imperial officials to sign, asking Emperor Zhaozong briefly transfer imperial authorities to the Crown Prince; he and Wang Zhongxian then took Shence Army soldiers to enter the palace to confront Emperor Zhaozong.
Sun then persuaded fellow officers Dong Yanbi (董彥弼) and Zhou Chenghui (周承誨) to join the plot as well.
On lunar new year's day in 901, Sun assassinated Wang Zhongxian and went to Shaoyang Pavilion to free Emperor Zhaozong and Empress He.