Inquisitions Post Mortem (IPMs) at The National Archives have been described as the single most important source for the study of landed society in later medieval England. Calendars of these documents for 1437-42 and 1442-47 have recently been published, and that for 1432-1437 is near completion. This book explores in detail for the first time the potential of IPMs as sources for economic, social and political history over the long fifteenth century. It shares findings about the making, use and 'reliability' of IPMs and develops our understanding of a source that is too often taken for granted - what did inquisitions seek to do, how were they compiled, how reliable were they? - while exploring how they can best be used for economic, demographic, place-name, estate and other kinds of study.