This is a unique volume examining the opposing air forces in the Spanish Civil War as well the intervention of the German, Italian, and Soviet air forces in their respective guises. The air campaigns fought during the Spanish Civil War prompted important technical and tactical developments for all parties, from the actual deployment of air power through communications. The small and largely obsolescent Spanish Air Force of 1936 grew into an effective fighting arm, which by 1937 had become a significant force, thanks, in part, to German and Italian support. The Nationalists fielded Heinkel, Fiat, and Messerschmitt fighters and Heinkel, Caproni, Savoia-Marchetti, Junkers, and Dornier bombers. These forces entered into a grinding battle of attrition over the less-organized but fiercely motivated Republican air arm over Aragon, and the Jarama and Madrid Fronts, and later over Brunete, Belchite, and the final campaign over the Ebro late in 1938.