Al-Mustansir (Baghdad)

Al-Mustansir Bi'llah (full name:Abû Ja`far al-Mustansir bi-llah al-Mansûr ben az-Zâhir Surname Al-Mustansir) was the penultimate Caliph of the Abbasid Caliphate from 1226 to 1242. He succeeded Caliph Az-Zahir in the year 1226.
Biography.
Al-Mustansir was born in Baghdad on 1192. On his father's death in 1226 he has succeeded his father Az-Zahir as the thirty-sixth Abbasid Caliph in Baghdad. Al-Mustansir is particularly known for establishing Mustansiriya Madrasah (currently a part of the Al-Mustansiriya University) in 1227/32/34. The Madrasah, at the time, taught many subjects including medicine, mathematics, literature, grammar and Islamic religious studies, becoming a prominent and high-ranking center for Islamic studies in Baghdad. 
 The Madrasas during the Abbasid period were used as the predominant instrument to foster the spread of Islamic thought as well as a way to extend the founder's pious ideals.
Al-Mustansir died on 5 December 1242. His son Al-Musta'sim succeeded him as the thirty-seventh and last Caliph of the Abbasid Caliphate.