Nationalism is one of the major social and political issues of modern times, and a subject of intense intellectual debate. The most important and influential theory of nationalism is that of Ernest Gellner (1925-1995). This volume assesses every aspect of that theory, bringing together an exceptional set of scholars to explain, criticise and move beyond Gellner's work. In doing so the book establishes the state-of-play within the theory of nationalism, and complements Gellner's account by bringing political variables back into play. The book is unique in offering sustained attention to a single powerful theory, and will be of wide interest to students and scholars of political and social theory, history, sociology and anthropology.