The Battle of the Ebro (Spanish: Batalla del Ebro, Catalan: Batalla de l'Ebre) was the longest and largest battle of the Spanish Civil War. It took place between July and November 1938, with fighting mainly concentrated in two areas on the lower course of the Ebro River, the Terra Alta comarca of Catalonia, and the Auts area close to Fayón (Faió) in the lower Matarranya, Eastern Lower Aragon. These sparsely populated areas saw the largest array of armies in the war.