A paleographic study developed between 2003 and 2010 by the Instituto Castellano Leonés de la Lengua, under the direction of Professor Jose Manuel Ruiz Asencio and features with the academic support that provides the Real Academia Española (RAE), signals the Cartulario of Valpuesta as the oldest written expression of Spanish, which would date from the 9th century.

This research confirms that the documentation of the Monastery of Burgos of Santa Maria de Valpuesta collects the oldest testimonies of the romance spoken in Castilla, locating thus Castilla y Leon as the Spanish community that has become, by its own right, cradle of the language.

The Cartulario of Valpuesta is a documentary made up of a total of 187 documents written in latin by 34 scribes from this monastery.

The double volume ‘Los Becerros Gotico y Galicano de Valpuesta’, inspired and edited by the Instituto Castellano Leones de la Lengua, and officially launched at the headquarters of the RAE (Real Academia Española), has become by its own right a solid work on which will underpin studies on the origins of language.