The Almohad dominance of Iberia continued until 1212 , when Muhammad III , `` al-Nasir '' ( 1199-1214 ) was defeated at the Battle of Las Navas de Tolosa in the Sierra Morena by an alliance of the Christian princes of Castile , Aragon , Navarre , and Portugal .
But by 1212 Muhammad III , `` al-Nasir '' ( 1199-1214 ) was defeated by an alliance of the four Christian princes of Castile , Aragón , Kingdom of Navarre and Portugal , at the Battle of Las Navas de Tolosa in the Sierra Morena .