The Battle of Las Navas de Tolosa, known in Arab history as the Battle of Al-Uqab (معركة العقاب), took place on 16 July 1212 and was an important turning point in the Reconquista and in the medieval history of Spain. The Christian forces of King Alfonso VIII of Castile were joined by the armies of his rivals, Sancho VII of Navarre, Peter II of Aragon and Afonso II of Portugal in battle against the Berber Almohad Muslim rulers of the southern half of the Iberian Peninsula. The Caliph al-Nasir (Miramamolín in the Spanish chronicles) led the Almohad army, made up of people from the whole Almohad empire.