The main objective of this paper is to analyze the institutions involved in library development in Spain at the stage where it begins to be applied for the first time in the country have a policy defined libraries and study how they influenced the subsequent evolution of this. Chronologically, the book focuses on the thirties and forties of the nineteenth century, when the suppression of religious communities in Spain took place, the nationalization of its assets and the establishment of a library-cultural policy to address the challenge of converting objects of art and literature of the convents and monasteries in domestic goods. This has not been an impediment to track the status of the Administration since the beginning of the century, and to provide information that goes beyond 1849 The book is organized into four main chapters. The first is intended to central government, which was the main institution responsible for library policy and the key to success or failure of it. In the second, the territorial authority (municipalities and county councils), representing the closest administrative bodies to citizens at the local level is studied. Third, the commissions created specifically to be occupied of national assets are analyzed. Finally, the role played by certain bodies, though not of the authority (such as universities or schools) or even were private entities (such as economic societies), left the imprint of his speech, often decisive detailed . The work has the advantage of widely used unpublished primary sources and weak diffusion, which brings unknown and very enriching for this type of study information. This is original research with a multidisciplinary approach that enables an all-encompassing knowledge of the phenomenon analyzed