Alfonso VIII

Alfonso VIII (1155-1214), king of Castile (1158-1214); he succeeded to the throne on the death of his father, Sancho III. Troubled by interference from Navarre in his youth, he later allied Castile with Aragón, forming a connection that was eventually to become the basis for the unification of Spain. He also established Castilian dominance over León. In 1170 he married Eleanor, daughter of King Henry II of England. From the 1170s, he resisted encroachments by the Almohads, Muslim invaders from northern Africa. Defeated by the Muslim caliph Yakub al-Mansur at Alarcos in 1195, Alfonso and his allies won a major victory over the Muslim commander al-Nasir at Navas de Tolosa in 1212.