There can be little doubting the significance of the Spanish Civil War, both as 'the last great cause' and as a defining moment on the road to the Second World War. In Spain, Mussolini and Hitler drew together in the Rome-Berlin Axis as they witnessed the pusillanimity of the democratic powers. This extensive collection of new research by an international team of scholars engages with the two central facts about the Spanish Civil War: in its origins, it was a series of Spanish social wars; and in its course and outcome, it was an episode in a greater European Civil War that ended in 1945. Uniquely focusing on the Spanish and international reasons for the ultimate defeat of the Second Republic, the chapters of this book show how, for three years, the Republic was besieged from without and from within: from outside, by the forces of international Fascism and their unwitting accomplices among the democratic states; and, from inside, by the forces of the extreme Left whose members put their own revolutionary ambitions before the effort to build a centralized war effort.