The military coup d'état that marked the beginning of the Spanish Civil War took place (and succeeded) in León on 20 July 1936, with the putschist military officers meeting little resistance. The Catholic Church adhered to the rebels and instrumentalised the Catholic sentiment and traditions against the Republic. The rebels expanded from the city to the rest of the traditionally conservative province, which remained under rebel control except a small northern part connected to Asturias, that became part of the battlefront until the fall of the North in October 1937. Both the Convent of San Marcos, the old Santa Ana factory and the provincial prison were nonetheless rehabilitated as mass detention camps in the city by the Francoist side.