This book examines the most important writings of a tenth century Islamic theologian and jurist who was one of the most original thinkers of his period. It argues that Qadi al-Nu"man"s works constituted new and vital genres in Ismaili Shi"i literature, an emergence necessitated by the Fatimids" transition from revolutionary movement to statehood, and by their desire to establish their authority as a Shi"i alternative to the Sunni Abbasid caliphate. Al-Nu"man, already famous in the Fatimid era, produced a legacy which consists of a school of law, historical and biographical works, new interpretations of Ismaili doctrine, and the formulation of a ceremonial language achieved through his work on court protocol.