He was a younger son of Sancho III of Navarre and Mayor of Castile, and by his father's will recognised the supremacy of his eldest brother, García Sánchez III of Navarre.
He was a younger son of Sancho III of Navarre and Mayor of Castile, and by his father's will. This father's will was recognised the supremacy of his eldest brother of Navarre. García Sánchez III was his eldest brother.