Al-Musta'sim, Iraqi caliph (b. 1213)
Abu Ahmad Abdallah ibn al-Mustansir Billah (Arabic: أبو أحمد عبد الله بن المستنصر بالله; 1213 – February 20, 1258), better known by his regnal name Al-Musta'sim Billah (المستعصم بالله) was the 37th and last caliph of the Abbasid dynasty; he ruled from 1242 until his death in 1258.