al-Qadir bi-llah Ahmad ibn Ishaq ibn al-Muqtadir

Al-Qadir Billah was the Abbasid caliph from 381 to 422 AH, acclaimed after al-Ta'i's deposition. He was known for piety, constant night prayer and much almsgiving; he studied fiqh under Abu Bishr al-Harawi and composed a work on the principles, and his caliphate lasted forty-one years and three months.

Al-Qadir Billah, Abu al-Abbas Ahmad ibn Ishaq ibn al-Muqtadir, was the Abbasid caliph from 381 to 422 AH. Acclaimed after al-Ta'i's deposition while absent, he arrived on the tenth of Ramadan and held a public sitting the next day with al-Sharif al-Radi reciting before him. Al-Suyuti reports from al-Khatib that he was known for piety, night prayer and much almsgiving; he studied fiqh under Abu Bishr al-Harawi and composed a work on the principles naming the Companions' virtues and declaring the Mu'tazila outside the faith — read every Friday in the hadith circle at al-Mahdi's mosque. In Shawwal he and Baha' al-Dawla swore loyalty to each other. Ibn al-Athir records him sending Ibn al-Baqillani to al-Radi's father demanding an apology for the verses on the Egyptian Mahdi. He died in 422 AH aged eighty-seven; his caliphate lasted forty-one years and three months.

Al-Qadir Billah, Abu al-Abbas Ahmad ibn Ishaq ibn al-Muqtadir, Abbasid caliph from 381 to 422 AH, born 336 AH to a bondwoman named Tamanna or Dumana. He was acclaimed after al-Ta'i's deposition while absent; he arrived on the tenth of Ramadan and held a public sitting the next day, congratulated, with al-Sharif al-Radi reciting before him. Al-Suyuti reports from al-Khatib that he was known for piety, constant night prayer and much almsgiving; he studied fiqh under Abu Bishr al-Harawi al-Shafi'i and composed a work on the principles naming the Companions' virtues and declaring the Mu'tazila and the Qur'an-created believers outside the faith — read every Friday in the hadith circle at al-Mahdi's mosque. In Shawwal of his accession year he held a great session where he and Baha' al-Dawla each swore loyalty to the other. Ibn al-Athir records that al-Sharif al-Radi's verses affirming the Egyptian Mahdi's lineage reached him, so he summoned the judge Abu Bakr ibn al-Baqillani and sent him to al-Sharif Abu Ahmad al-Musawi, al-Radi's father, demanding an apology. He died Monday night, the eleventh of Dhu al-Hijja 422 AH, aged eighty-seven; his caliphate lasted forty-one years and three months.