Seal of King Sancho VII of Navarre (Reverse)The eagle commonly known as "Arrano Beltza"  (The Black Eagle Emblem)
Menéndez Pidal, Faustino (2004). El Escudo de España. Madrid, Real Academia Matritense de Heráldica y Genealogía. ISBN 84-88833-02-4
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Heralder Elements of File:Arrano Beltza.svg