`Abbasid caliph, reigned from 255/869 to 256/870, son of al-Wathiq.
al-Muhtadi had initially been promoted by a number of officials following the death of his father, al-Wathiq. Instead, al-Mutawaqqil was promoted to the caliphate. After the deposition and murder of al-Mutwakkil's son al-Mu`tazz in 255/869 did al-Muhtadi finally come to power. He looked towards the reign of the Umayyad caliph `Umar b. `Abd al-`Aziz for inspiration, noted for his piety, simplicity, and the strength with which he attempted to raise the position of the caliphate back to its past power. In this way, he was interested in direct rule by the caliph, he often sat over mazalim sessions, sessions in which the caliph himself heard and responded directly to petitions.
His reign saw a number of `Alid revolts in the provinces, but the Turkish general Musa b. Bugha remained the most serious enemy of the caliphate. Upon hearing of the accession of al-Muhtadi, Musa returned to Samarra from the front, where he had been fighting against an `Alid uprising and forced al-Muhtadi to pledge an oath against the Turkish chief Salih b. Wasif. When Salih went into hiding, the Turkish soldiery mutinied with the intent of deposing al-Muhtadi. al-Muhtadi was forced to offer a pardon to Salih, but when Salih did not return, the Turks pillaged Samarra until Musa came and scattered them. When Salih did return from his concealment, Musa killed him.
When Musa b. Bugha went on campaign against the Kharijites, al-Muhtadi began to incite the people against Musa and his brother Muhammad b. Bugha. Muhammad was tried for embezzlement and, after the caliph had promised him a pardon, he was put to death. al-Muhtadi realized that the only way to save himself after that was to move against Musa, but Musa was informed of the caliph's moves in advance and he was able to move his superior forces against Samarra. al-Muhtadi refused to abdicate and Musa had him killed and replaced with the son of al-Mutawakkil al-Mu`tamid.
The reing of al-Muhtadi and his attempts at returning direct rule into the hands of the caliph demonstrates just how powerful the Turkish officers had become by the middle of the third century AH.
Zettersteen, K.V. "al-Muhtadi bi'llah" translated by C.E. Bosworth in EI2.
255 - Sha`ban - al-Mu`tazz dies. al-Muhtadi accends to the caliphate.
256 - Muharram - Musa b. Bugha reaches Samarra and forces al-Muhtadi to pledge an oath against Salih b. Wasif.
- Rajab - al-Muhtadi killed by the forces of Musa b. Bugha.