In March 1938, the Nationalist forces launched the Aragon Offensive, a massive campaign that broke through the Republican lines and advanced rapidly toward the Mediterranean. The offensive, which involved 150,000 troops and 900 aircraft, was a devastating blow to the Republic, as it split the Republican-held territory in two and cut Catalonia off from the rest of Republican Spain. The Nationalist victory at the Battle of Caspe on March 16-17 was a key moment in the campaign, which effectively sealed the Republic's fate.

The Aragon Offensive was a theme of despair in Republican poetry, as writers chronicled the collapse of the front and the flight of refugees. The offensive also inspired poetry among the International Brigades, who fought desperate rearguard actions to slow the Nationalist advance. The poetry of this period increasingly emphasized the inevitability of defeat, as the Republic's military situation deteriorated.