Abū Muḥammad ʿAlī ibn Aḥmad (; 877/78 – 13 August 908), better known by his regnal name al-Muktafī bi-llāh (), was the Caliph of the Abbasid Caliphate from 902 to 908. More liberal and sedentary than his militaristic father al-Mu'tadid, al-Muktafi essentially continued his policies, although most of the actual conduct of government was left to his viziers and officials. His reign saw the defeat of the Qarmatians of the Syrian Desert, and the reincorporation of Egypt and the parts of Syria ruled by the Tulunid dynasty. The war with the Byzantine Empire continued with alternating success, although the Arabs scored a major victory in the Sack of Thessalonica in 904. His death in 908 opened the way for the installation of a weak ruler, al-Muqtadir, by the palace bureaucracy, and began the terminal decline of the Abbasid Caliphate. Early life Ali ibn Ahmad was born in 877/8, the son of Ahmad ibn Talha, the future caliph al-Mu'tadid () by a Turkish slave-girl, named Čiček ("flower", Jījak in Arabic). He was the first caliph named after caliph Ali. 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. Following his rise to the throne, al-Mu'tadid continued his father's policies, and restored caliphal authority in the Jazira,