The Spanish Civil War was the most important conflict in Europe in the decade prior to World War II and has generated an enormous literature. Even after the passage of three generations it continues to stimulate interest. The controversies ignited by the war still find partisans, well beyond Spain, while within the country the war continues to play a dominant role both in historiography and in partisan discourse.

The first objective history, published by Hugh Thomas in 1961, was expanded into a more thorough 1,100-page work sixteen years later. Though no single volume can capture completely and definitively a conflict that was as complex as the French Revolution, the revised edition of Thomas remains unsurpassed as a single-volume narrative. The present book does not offer an exhaustive description of the war, but tries to clarify the key issues, discussing the most salient themes within an analytical and comparative framework, while incorporating the results of the most recent research. It especially seeks to respond to the injunction of José Ortega y Gasset in 1938 that the most important thing to understand about the war is the nature of its origins.