The Kingdom of Aragon started off as an offshoot of the Kingdom of Navarre. It was formed when Sancho III of Navarre decided to divide his large realm among all his sons. Aragon was the portion of the realm which passed to Ramiro I of Aragon, an illegitimate son of Sancho III. The kingdoms of Aragon and Navarre were several times united in personal union until the death of Alfonso the Battler in 1135.