In the English-speaking world, the Spanish Civil War is perhaps best remembered through the exploits of thousands of foreign volunteers from across the globe who joined the International Brigades - a force of communists, socialists and others who took their opposition to fascism to extraordinary lengths. Their passionate political commitment to Spain's cause and determination in battle placed them among the crack troops of the Republic's People's Army.

Yet while much has been written about the political, social and cultural significance of the brigades and their experience in Spain, less has been said about their performance as front-line troops. It is this military history that Alexander Clifford focuses on in vivid detail in this highly illustrated new study which reassess their impact within the Republican People's Army.

His account tells the story of the brigades as combat units, tracing the course of each major battle in which they fought and showing the drastic changes they underwent as the war progressed - from an untrained militia in 1936, to the tried and tested shock troops of 1937, to a shadow of their former selves by 1938 after repeated maulings and the introduction of Spanish conscripts to fill their ranks.