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.
[2] After al-Muhtadi was deposed by the Turkish commanders Bayakbak and Yarjukh, he was selected by the military as his successor and proclaimed Caliph with the regnal name al-Muʿtamid ʿAlā 'llāh on 16 or 19 June 870.
Immediately he hastened north to Samarra, where he and Musa ibn Bugha effectively sidelined al-Mu'tamid, and assumed control of the government.
[12] Within a short time, Abu Ahmad was conferred an extensive governorate covering most of the lands still under caliphal authority: western Arabia, southern Iraq with Baghdad, and Fars.
In a succession of engagements in the marshes of southern Iraq, the Abbasid forces drove back the Zanj towards their capital, Mukhtara, which fell in August 883.
Ibn Tulun and the Abbasid regent fell out in 875/6, on the occasion of a large remittance of revenue from Egypt to the central government.
[19] Al-Muwaffaq, who in his fight against the Zanj considered himself entitled to the major share of the provincial revenues, was angered by this, and by the implied machinations between Ibn Tulun and his brother.
[20][15] In a public gesture of support for al-Mu'tamid and opposition to al-Muwaffaq, Ibn Tulun assumed the title of "Servant of the Commander of the Faithful" (mawlā amīr al-muʾminīn) in 878.
[19] With the support of al-Mu'tamid, in 877/8 Ibn Tulun managed to be assigned responsibility for the entirety of Syria and the Cilician frontier zone (Thughur) with the Byzantine Empire.
[19] In 881, Ibn Tulun added his own name to coins issued by the mints under his control, along with those of the Caliph and heir apparent, al-Mufawwad.
The garrison commander of Baghdad, and the vizier Isma'il ibn Bulbul, hatched a plot to keep Abu'l-Abbas imprisoned and allow power to pass to al-Mu'tamid.
[12] The powerless al-Mufawwad was pushed aside on 30 April 892,[26] and when al-Mu'tamid died on 14 October 892,[27] "apparently as a result of a surfeit of drink and food" (Hugh N. Kennedy), al-Mu'tadid took power as caliph.