At the time of his birth, the Abbasid Caliphate was still reeling from the decade-long civil war known as the "Anarchy at Samarra", which had begun with the assassination of Caliph al-Mutawakkil () by dissatisfied soldiers and ended with the accession of al-Mu'tamid (). Real power, however, lay with al-Mu'tamid's brother, al-Muwaffaq, Ali's paternal grandfather. Al-Muwaffaq enjoyed the loyalty of the military, and by 877 had established himself as the "de facto" ruler of the state. Caliphal authority in the provinces collapsed during the "Anarchy at Samarra", with the result that by the 870s the central government had lost effective control over most of the Caliphate outside the metropolitan region of Iraq. In the west, Egypt had fallen under the control of Ahmad ibn Tulun, who also disputed control of Syria with al-Muwaffaq, while Khurasan and most of the Islamic East had been taken over by the Saffarids, who replaced Abbasids' loyal clients, the Tahirids. Most of the Arabian peninsula was likewise lost to local potentates, while in Tabaristan a radical Zaydi Shi'a dynasty took power. In Iraq, the rebellion of the Zanj slaves threatened Baghdad itself, and it took al-Muwaffaq and al-Mu'tadid years of hard campaigning before they were finally subdued in 893.