Royal crest of the former Crown of Castile, used as Royal crest of the Spanish Monarchs (16th-19th Centuries), Castilian Arms had precerence in their arms.
Menéndez-Pidal De Navascués, Faustino; El escudo; Menéndez Pidal y Navascués, Faustino; O´Donnell, Hugo; Lolo, Begoña. Símbolos de España. Madrid: Centro de Estudios Constitucionales, 1999. [[:en:ISBN|ISBN 84-259-1074-9]]
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