 Apparently born before 1007, he was the illegitimate son of Sancho III of Pamplona by his mistress Sancha of Aybar.Ramiro was reputed to have been adopted by his father's wife Muniadona after he was the only one of his father's children to come to her aid when needed, although there is no surviving record of these events and the story is probably apocryphal.During his father's reign, he appeared as witness of royal charters starting in 1011, and was given numerous properties in the county of Aragon, and by the division of Sancho's realm on the latter's death in 1035, the county of Aragon fell to Ramiro with the title of "baiulus" or steward.