After the revolution of 1934, nearly 750 revolutionary convicts were imprisoned there. Most of them were amnestied after the electoral win of the left in February 1936. During the early stages of the Civil War (July-September 1936), the military rebels strong in Navarre unleashed a terror campaign against inconvenient, dissenting civilians in the rearguard. The inmate population in the fort rose to more than 2,000.