This develops the concepts and tools for the systematic study of the mechanics of survival medieval Islamic books. These concepts and tools are then applied to studying the history of the earliest extant biographical dictionary of the Islamic tradition Ibn Sa'd's Tabaqat. First, the book's transmitters and their historical contexts are investigated using a large number of transmission chains. Then, conclusions are extracted from this data concerning the book's authorship, the survival process of its many versions, and the trajectories of its geographical diffusion at different phases of its long life.