The present work intends to value t

The present work intends to value the family archives as a source of research for the written culture in the XVIII and XIX centuries. For this, the author reflects on the possibilities offered by the archives of the medium oligarchies, very numerous and unknown, at the same time poorly organized, taking as reference the Archive of the Marquises of Corvera, united around the lineage of the Bustos, which in turn contains various files of families of different social levels. Special attention is paid to the transmission of written culture within the lineage through testamentary trusts, the professional use of written culture in family administrations and the cultural level of the different social classes related to these administrations, which it observes mainly in the correspondence, the accounts presented by the administrators and the inventories of goods of the houses.