The mobilisation of resources during the Spanish Civil War extended even into the areas of Culture, Patrimony and Heritage. Although the most well known initiatives in Heritage Management are those concerning the Prado Museum or the National Library, since the beginning the creation of a War Archive that would gather written testimonies of all the military units or political associations that fought in defense of the Republic was considered. After the outcome of war, this archive was confiscated and lost its original nature. The documents that composed it ended up in several different conservation centres and are currently disseminated under other pretences. With this material presently fragmented, it has been possible to reconstruct the archive history and destiny after the war. Moreover, this historical reconstruction has allowed to re-establish the true purpose and nature of this archiving initiative as an element of fight and propaganda, it uses its records to narrate the social mobilisation that took place in defense of the Republic. Recently, spontaneous initiatives, that related to the Civil War archive, have succeeded in converting archives into a living instrument with a social function and class claims.