Casanova explores the concept of anarchism as both a political ideology and a social movement during the Second Republic and the Civil War (1931-39). Dividing the work into two parts, the author first explores anarchism's strained relations with the Republic, and then goes on to analyse the revolutionary process that broke out in the summer of 1936. The Spanish Civil War became the setting for the struggle between revolution and counter-revolution as well as being, for many outsiders, the place of armed conflict between the forces of democracy and fascism. This book is a path-breaking synthesis of political, social and cultural history concerning the anarchist revolution during the Spanish Civil War by Spain's leading historian of the Civil War. This completely new study also examines possible reasons why anarch-syndicalism did not resurface after the death of Franco and offers a commentary on other writings on anarchism in contemporary Spain.