Mosén Diego de Valera (1412–1488) was a nobleman, writer, and historian from the Crown of Castile who has been described as having had "chivalrous adventures" that took him "as far as Bohemia" where he was a participant in the Hussite Wars.
[1] One treatise written by Valera, Espejo de verdadera nobleza (1439–41), challenged some of the preconceived notions concerning nobility.
[2] He also wrote one of the first known books on fencing, Treatise on Arms, and a short history of Spain, the Crónica de España abreviada (1481), which itself relies on the Chronicle of 1344.
[5] At the beginning of 1447, being a procurator in Cuenca and after intervening in the courts with brief speeches, he addressed a letter to the king emphasizing the need to preserve peace with France.
The letter caused such an impact that a copy was brought into the hands of the noble Don Pedro de Estúñiga, who entrusted him with the education of his grandson.