On the death of Sancho III of Navarre in 1035, the Kingdom of Navarre is divided in to three parts: (1) Navarre and the Basque country, (2) Castile and (3) Sobrarbe, Ribagorza and Aragon.

As the most important Christian monarch in Iberia and the King of All Spain, each of his three lands are converted into a Kingdom.

Sancho's son Gonzalo inherits Sobrarbe and Ribargorza, but Gonzalo is killed soon after and all the land he owns goes to his illegitimate brother Ramiro, creating the future Kingdom of Aragon.

By defeating his brother, García Sánchez III of Navarre, Ramiro achieves virtual independence for Aragon.