Abu Ja'far al-Mansur ibn al-Zahir[a] (17 February 1192 – 2 December 1242), commonly known as al-Mustansir I,[b] was the 36th Abbasid caliph, ruling from 1226 to 1242.

His full name was Mansur ibn Muhammad al-Zahir and his Kunya was Abu Jaʿfar.

His father, lowered the taxes of Iraq, and built a strong army to resist invasions.

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.

After Al-Mustansir's accession to the throne, Khata presented Shahan to him as a gift, as part of a group of slaves.