Background
On his father's death in 1226 he has succeeded his father Az-Zahir as the thirty-sixth Abbasid Caliph.
On his father's death in 1226 he has succeeded his father Az-Zahir as the thirty-sixth Abbasid Caliph.
Al-Mustansir died on 2 December 1242. Mustansiriya Madrasah, was established in 1227 (or 1232/34 AD by some accounts) by the Abbasid Caliph Al-Mustansir and was one of the oldest universities in the world. Its building, located on the left bank of the Tigris River, survived the Mongol invasion and has been restored.