Abu Sa'id was succeeded by his son, Abu-l-Hasan 'Ali ibn 'Uthman, who seized Tilmisan in 1332.[1] In 1333, Abd al-Malik, crossed the Straits of Gibraltar and defeated the Castilians who occupied the region since 1309.[2] When Abd al-Malik died his father, Abu al-Hasan, led another invasion in 1340 onto the Iberian Peninsula but was defeated by a coalition of forces from Castile and Portugal at the Salado River.[13] While the war helped unite the Muslim Naṣrid dynasty of Granada and slowed the advance of the Christians toward the Strait of Gibraltar, no land was taken from the Christians. This defeat significantly changed the balance of power in favour of Christians forcing the Marinids to retreat to Morocco and to abandon their objective of domination of the Iberian Peninsula.