Abu’l-ʿAbbās Aḥmad ibn Jaʿfar, better known by his regnal name al-Muʿtamid ʿalā ’llāh, was the caliph of the Abbasid Caliphate from 870 to 892. His reign marks the end of the "Anarchy at Samarra" and the start of the Abbasid restoration, but he was largely a ruler in name only. Power was held by his brother al-Muwaffaq, who held the loyalty of the military. Al-Mu'tamid's authority was circumscribed further after a failed attempt to flee to the domains controlled by Ahmad ibn Tulun in late 882, and he was placed under house arrest by his brother. In 891, when al-Muwaffaq died, loyalists attempted to restore power to the Caliph, but were quickly overcome by al-Muwaffaq's son al-Mu'tadid, who assumed his father's powers. When al-Mu'tamid died in 892, al-Mu'tadid succeeded him as caliph.

The Anarchy at Samarra was a period of extreme internal instability from 861 to 870 in the history of the Abbasid Caliphate, marked by the violent succession of four caliphs, who became puppets in the hands of powerful rival military groups.