Al-Muntasir was the son of Al-Mutawakkil and succeeded him as caliph in 861. He was only a child at the time, and his reign was dominated by his regent, the eunuch Ahmad ibn al-Khasib. Al-Muntasir was murdered in 862 by his brother, Al-Mu'tazz, who then succeeded him as caliph.
Unmasking Al-Mutawakkil: The Rise and Reign of the 10th Abbasid Caliph