Al-Qadir

'''Abu'l-Abbas Ahmad ibn Ishaq (; 28 September 947 – 29 November 1031), better known by his regnal name al-Qadir''' (, , ), was the Abbasid caliph in Baghdad from 991 to 1031.

Born as an Abbasid prince outside the main line of succession, al-Qadir received a good education, including in the tenets of the Shafi'i school of Islamic jurisprudence. He rose to the throne after his cousin, at-Ta'i, was deposed by the Buyid ruler of Iraq, Baha al-Dawla. Although still under Buyid tutelage and with limited real power even in Baghdad, al-Qadir was able to gradually increase the authority of his office over time, exploiting the rivalries of the Buyid emirs and the caliphate's role as a fount of legitimacy and religious guidance. Al-Qadir was able to nominate his own heirs without interference by the Buyids, and was instrumental in securing control of Baghdad for the Buyid emir Jalal al-Dawla. At the same time, he sought champions further afield, notably in the person of Mahmud of Ghazni, who sought caliphal recognition for his conquests, providing funds in return. In the religious sphere, al-Qadir placed himself as the champion of Sunni Islam against Shi'a Islam, represented by the Buyids as well as by the Fatimid Caliphate of Cairo. He denounced the Fatimids in the Baghdad Manifesto of 1011, and issued proclamations that for the first time codified Sunni doctrine in the so-called 'Qadiri Creed', taking the side of the traditionalist Hanbali school against the rationalist Mu'tazilites. Al-Qadir's religious policies cemented the Sunni–Shi'a split, as the followers of divergent doctrines were denounced as infidels and made licit to be killed as a result. His reign heralded the re-emergence of the Abbasid caliphate as an independent political actor, and presaged the so-called 'Sunni Revival' later in the century.