We must look for the background of the LBF in 1970, when the Benedictine Juan José Aguirre took charge of the library of the Benedictine monastery of Lazkao. He learned the trade in the library of Montserrat, and returned to Lazkao with all the baggage of what he had seen and learned there. He organized and catalogued the monastery library and expanded it with new books and magazines; he also created a new section, the Basque Library. Not only that, he began to compile a type of fonds that the rest of the libraries and archves did not keep at that time, either because of their peculiar format (pamphlets, posters, stickers...) or because they had appeared in exile or in hiding. Agirre's purpose was to create a large archive on Basque issues.
And to this he dedicated himself for more than four decades, helped by the wide network of volunteers he created around him for the collection of material. Organizing and describing what he received, opening the doors to researchers... Agirre contributed to save an important part of the Basque documentary heritage, and this brought him the recognition of institutions and society.