Diego de Valera and his Treatise on Coats of Arms (15th century)
Monuments of heraldic reflection – heraldic treatises – are of particular value. Diego de Valera grew up among the Castilian nobility at the be-ginning of the 15th century, began a knightly «caree»" at the age of 15, and was elevated to the dignity of knighthood. He visited many Euro-pean countries, took part in tournaments. He is one of the most famous writers of the late Middle Ages, the author of a number of works on topics related to chivalry. «Treatise on Coats of Arms» (Tratado de las armas) (1458–1467) Valera follows the European traditions of heraldic treatises. Along with other theoretical texts on chivalry, it contains chapters on the origin of coats of arms, coat of arms cotta and banners. The presence of the heraldic part in the treatise is due to the participa-tion of the heraldic officials in the procedure of the duel. Valera's trea-tise makes up for the lack of heraldic material of the sources, which is available in relation to Castile of the 15th century. «Treatise on Coats of Arms» had a huge impact on all subsequent heraldic treatises on the Iberian Peninsula. Diego de Valera's treatise can be considered the founder of the era of the Castilian heraldic treatises, which determined their theme.