Irún is located on the northeastern coast of Spain, between the French border and the city of San Sebastian. Navarre, a Carlist stronghold, was taken over by the Requetés in late July, followed by brutal mass-repression against blacklisted civilians. In early August, the Carlists Colonel Jose Solchaga Zala and Colonel Alfonso Beorlegui under the orders of General Mola commanded large numbers of Requetés down the north of Navarre towards Irún. Colonel Beorlegui's force was smaller, but it included 155 mm artillery, German light tanks, Junkers Ju 52 bombers, and a 700-man bandera from the Spanish Foreign Legion. It also included Italian aircraft. Both Germans and Italians carried out heavy air strikes over Irun and Hondarribia on a daily basis, at the same time dropping pamphlets over the towns threatening to repeat the massacres of Badajoz. The town was defended by 3,000 Republicans, including CNT militia, Asturian miners, Basque nationalists, and French communist volunteers. However, they were poorly armed and lacking in proper military training.
The battle
The Nationalist ships España, Almirante Cervera, and Velasco bombarded the town on August 11. The main fighting took place on the Puntza ridge south of the town. The peak of the battle occurred at the convent of San Marcial, which was defended by Asturian miners and militia who threw dynamite and rocks when they ran out of ammunition. The French had closed the border with Spain on August 8, leading to a shortage of ammunition and supplies on the Republican side. When the Republicans finally abandoned the town, anarchist forces in retreat enraged by their lack of ammunition set fire to parts of the town to destroy things that might aid the Nationalists. During the duration of the war, when the Nationalists bombarded then occupied a town, they would put the blame of the destruction on the Republicans, like in Gernika, citing the example of Irún. Beorlegui was wounded by a sniper's bullet when he entered the town. He refused to have the wound treated and soon died from gangrene. Thousands of civilians and militias fled in panic for their lives across the Bidasoa border to France as the rebel far-right forces entered the town. The Nationalist battalions headed then west towards San Sebastián, defended halfway only by the Fort San Marcos.