The Buddhist monk Fazang (643-712), regarded today mainly as a scholastic monk, was in fact one of the greatest metaphysicians in Asia. This biographical - and hagiographical - study of Fazang seeks to explore his other contributions and in so doing to correct some major mis-presentations and misinterpretations existing in modern scholarship. It highlights and uncovers aspects of Fazang's complicated life which have been neglected or ignored until now. By experimenting with some methodological innovations in reading medieval Chinese monastic hagio-biography, this study reveals general features, structures and overall governing laws of medieval East Asian monastic hagio-biographic literature. In doing so it is a major contribution to the ongoing discussion among scholars of hagiography in other contexts as well.