Ferdinand III, called the Saint, was King of Castile from 1217 and King of León from 1230 as well as King of Galicia from 1231. He was the son of Alfonso IX of León and Berengaria of Castile. Through his second marriage he was also Count of Aumale. Ferdinand III was one of the most successful kings of Castile, securing not only the permanent union of the crowns of Castile and León, but also masterminding the most expansive southward territorial expansion campaign yet in the Guadalquivir Valley, in which Islamic rule was in disarray in the wake of the defeat of the Almohad caliphate at the Battle of Las Navas de Tolosa. His repeated and decisive victories against the Islamic Caliphate earned him the title Athleta Christi, meaning 'Champion of Christ', which was conferred upon him by Pope Gregory IX.
