The crisis in the Almohad Caliphate, however, remained unresolved. In 1228, a new Almohad pretender, Abd al-Ala Idris I 'al-Ma'mun', decided to abandon Spain, and left with the last remnant of the Almohad forces for Morocco. Al-Andalus was left fragmented in the hands of local strongmen, only loosely led by Muhammad ibn Yusuf ibn Hud al-Judhami. Seeing the opportunity, the Christian kings of the north - Ferdinand III of Castile, Alfonso IX of León, James I of Aragon and Sancho II of Portugal - immediately launched a series of raids on al-Andalus, renewed almost every year. There were no great battle encounters - Ibn Hud's makeshift Andalusian army was destroyed early on, while attempting to stop the Leonese at Alange in 1230. The Christian armies romped through the south virtually unopposed in the field. Individual Andalusian cities were left to resist or negotiate their capitulation by themselves, with little or no prospect of rescue from Morocco or anywhere else.