He was the natural son of Sancho III of Navarre.
In 1035 he inherited the small valley of the Aragon River (the northwest corner of the modern province of Huesca) with the title of 'king'. After the death of his brother Gonzalo in 1045, he obtained as well the kingdoms of the Sobrarbe (the central north strip of the modern province of Huesca) and the Ribagorza (the northeast corner of that province).
He died at the siege of Graus.
Sancho III of Navarre
|List of Aragonese monarchs||
Sancho I of Aragon