The Republican army surrounded around 1,200 rebel civil guards and falangists who supported the Nationalists and forced them to surrender after a protracted offensive.

After the failed coup of July 1936 in Andalusia, many groups of rebel civil guards retreated from their garrisons to hilltops, monasteries and others easily defensible points, living by robbing from the neighborhood.

During the first months of the war, there had been no attack launched against this enclave, because the Republican committee of Andújar did not know that the civil guards of the shrine were rebels.

After gathering a good supply of food, the civil guards decided to send a declaration of war to the committee in September 1936.

In April 1937, the Republican government decided to crush the resistance of the rebels and sent a large force (20,000 men), led by communist major Martínez Cartón.