Concerning the life and achievements of monk Daoyin of the Tang dynasty, a most detailed record has previously been found in Biographies of the Eminent Monks of the Song Dynasty. The discovery of Dunhuang manuscripts at the beginning of the 20th century provides further material about the life of this extraordinary monk. After careful study of these unearthed documents, this research presents a detailed catalogue of the activities and achievements of Daoyin’s life. While living as a monk at the Jianfu Temple in Chang’an in the sixteenth year of the Kaiyuan era（728 CE）, Daoyin presided over the Fasting Gathering at Yixing Pagoda with Emperor Xuanzong in attendance. His regular activities at the temple were focused on the study of esoteric Buddhist teachings. He was known to possess a text entitled “Dongxia xianzheng lveji” 东夏显正略记 （Promoting Uprightness in Dongxia Kingdom） which seems to have consisted of the collection of notes he made while studying the differences between Buddhist and Taoist theories on equilibrium. Daoyin was a disciple of Huizhao 惠 沼 and was crucial to Chinese studies of Yogacara philosophy during the Kaiyuan period, which would explain why the text of “Yu zhu jingang banruo jing xuanyan” 御注金刚般若经宣演 （Promotion of the Prajna Paramita Sutra with Imperial Commentary） which he wrote features a Yogacara perspective. In his later life, he lived as a hermit due to illness and concentrated on writing, he was also elected as one of the “Ten Worthies” of the palace temple. None of the above information is present in Biographies of the Eminent Monks of the Song Dynasty and other received sources, which makes these Dunhuang documents essential to improving our knowledge and understanding of Daoyin’s life and thought.
