Before 1035 , Sancho decreed that Gonzalo should rule Sobrarbe and Ribagorza .
He was the son of King Sancho III of Pamplona and his wife , Muniadona of Castile .
Before 1035 , Sancho III decreed that son should rule Sobrarbe and Ribagorza .
He was the son of King Sancho III of Pamplona and his wife , Muniadona of Castile .