On the death of the former Caliph, al-Muqtadir, the courtiers, who feared that his son might revenge his father's death upon them, chose instead the late Caliph's brother al-Qahir; but he was an even worse lord than al-Muqtadir. With an outward affectation of godliness, he went to every excess of cruelty and extortion. He even tortured the mother of al-Muqtadir and his sons and favorites, to squeeze from them the wealth built up throughout the late reign. Many fled from his grasp.
The Caliph had his nephew, who was to have followed him, walled up alive. Al-Qahir, thus relieved from immediate threat, broke out into such tyranny, evenly against friend and foe, as to make his rule unbearable. A fresh conspiracy was begun, and the Caliph, overcome at night by wine, was set upon in his palace.
Refusing to abdicate, his eyes were blinded, and he was cast into prison in 322 AH (934 CE). Eleven years later he was freed, and was sometimes seen in beggar's rags and wooden sandals;—sad contrast to his high-sounding name, al-Qahir bi’llahi, "Victorious by the will of God."