On July 24, 1936, the Durruti Column, an anarchist militia named after the legendary Buenaventura Durruti, left Barcelona for the Aragon front to fight against the Nationalist forces. The column, which was composed of some 3,000 anarchist volunteers, played a significant role in the early defense of the Republic, fighting in the battles for Zaragoza and Madrid. Durruti himself was killed in the Battle of Madrid on November 19, 1936, becoming a martyr for the anarchist cause.

The Durruti Column inspired a number of poems and songs, both in Spain and abroad, that celebrated the heroism of the anarchist volunteers. The column became a symbol of the revolutionary spirit of the early war, and its members were praised by poets who saw the anarchist militias as the embodiment of the anti-fascist struggle. Durruti's death was particularly mourned in anarchist poetry, which saw him as a fallen hero.