Ar-Radi, Abbasid caliph (b. 909)
Abu'l-Abbas Ahmad (Muhammad) ibn Ja'far al-Muqtadir (Arabic: أبو العباس أحمد (محمد) بن جعفر المقتدر, romanized: Abū al-ʿAbbās Aḥmad (Muḥammad) ibn al-Muqtadir; December 909 – 23 December 940), usually simply known by his regnal name al-Radi bi'llah (Arabic: الراضي بالله, romanized: al-Rāḍī bi'llāh, lit. 'Content with God'), was the twentieth Caliph of the Abbasid Caliphate, reigning from 934 to his death. He died on 23 December 940 at the age of 31. His reign marked the end of the caliph's political power and the rise of military strongmen, who competed for the title of amir al-umara.