His Taoist name was Cizang, born around the 18th year of the Zhenguan era of the Tang Dynasty (644), and passed away in the 29th year of the Kaiyuan era (741). He was a native of Jingzhao Prefecture in the Tang Dynasty (present-day Guanzhong, Shaanxi). He was once a Taoist priest, skilled in medicine, and served as a royal physician during the reign of Empress Wu Zetian (684-690). He was renowned alongside the famous physicians Zhang Wenzhong and Li Qianzong, and was once summoned with Zhang Wenzhong to diagnose the illness of Su Liangsi. During the Jinglong era of Emperor Zhongzong (707-710), he served as the Minister of Imperial Banquets, in charge of the royal diet, already in his seventies. He soon retired and returned to his hometown. He dispensed medicine to help people and practiced medicine among the populace, often accompanied by a black dog. Emperor Xuanzong valued his skills and summoned him to the court, but he declined the official position and returned to his hometown, revered by the world as the Medicine King. Emperor Xuanzong bestowed upon him the title of Medicine King, and after his death, he was enshrined in the Medicine King Temple.