Glosas Emilianenses

The Glosas Emilianenses (Spanish for "glosses of [the monastery of Saint] Millán/Emilianus") are glosses written in the 10th or 11th century to a 9th-century Latin codex called the Aemilianensis 60; the name Glosas Emilianenses is also sometimes applies to the entire codex. These marginalia are important as early attestations of both an Iberian Romance variety (similar to modern Spanish or Navarro-Aragonese) and of medieval Basque. The anonymous author of the glosses, presumed to be a monk at the monastery San Millán de Suso, wrote the glosses in three languages:

• A simplified version of Latin
• The medieval form of a Hispanic Romance language (traditionally regarded as Castilian or Old Spanish, but now most often classified as Navarro-Aragonese or a related dialect);
• Medieval Basque

The latter two would have been the vernacular languages in the region surrounding the monastery, although there is a possibility that the author of the glosses was a newcomer in the area.

The literary critic and director of the Instituto Castellano y Leonés de la Lengua Gonzalo Santonja has argued that the language of the Glosses is a "Latin language assaulted by a living language of the street which has crept into these writings".

The Glosses were formerly considered to include the first instances of early Spanish. However, in November 2010, the Real Academia Española declared that the first appearances of written Spanish can be found in the Cartularies of Valpuesta, IX century documents in an evolved Latin from the province of Burgos.