Alfonso I, called the Battler or the Warrior, was King of Aragon and Navarre from 1104 until his death in 1134. He was the second son of King Sancho Ramírez and successor of his brother Peter I. With his marriage to Urraca, queen regnant of Castile, León and Galicia, in 1109, he began to use, with some justification, the grandiose title Emperor of Spain, formerly employed by his father-in-law, Alfonso VI. Alfonso the Battler earned his sobriquet in the Reconquista. He won his greatest military successes in the middle Ebro, where he conquered Zaragoza in 1118 and took Ejea, Tudela, Calatayud, Borja, Tarazona, Daroca, and Monreal del Campo. He died in September 1134 after an unsuccessful battle with the Muslims at the Battle of Fraga.

The Kingdom of Navarre, originally the Kingdom of Pamplona, was a Basque kingdom that occupied lands on both sides of the western Pyrenees, with its northernmost areas originally reaching the Atlantic Ocean, between present-day Spain and France.