With the offensive of Aragon in 1938, the republican chief of staff, General Vicente Rojo, set up his operations center in this city, concentrating there all the International Brigades that he was able to gather. On March 15 the Battle of Caspe began, when three Francoist divisions of the Moroccan Army Corps reached the suburbs of the town. The 1st Division of Navarra undertook the siege of Caspe, being present, in the first phase of the battle, the International Brigades XI, XIII and XV; In a second phase that took place on the right bank of the Guadalope river, XII and XIV intervened. Although the interbrigadistas, especially those of the XV Brigade, deployed a strong defense against the attackers, at dusk on March 17 the town was finally conquered by Franco's troops. The war part of the "national" side recorded the fact with these words: This morning the important city of Caspe has been occupied, also establishing a bridgehead 5 kilometers to the east, despite the stubborn resistance opposed by five international brigades. After the conquest, the town became the headquarters of the Moroccan Army Corps, in charge of the troops of the Ebro river.
