786 births

Abū al-ʿAbbās Abd Allāh ibn Hārūn al-Maʾmūn (; 14 September 786 – 9 August 833), better known by his regnal name '''al-Ma'mun''' (), was the seventh Abbasid caliph, who reigned from 813 until his death in 833. His leadership was marked by the power and prosperity of the Abbasid Caliphate, al-Ma'mun promoted the Graeco-Arabic translation movement, the flowering of learning and the sciences in Baghdad, and the publishing of al-Khwarizmi's book now known as "Algebra", making him one of the most important caliphs in the Islamic Golden Age. He is also known as a proponent of the rational Islamic th

Emperor of Japan

Medieval Arab mathematician

Japanese empress (786-850)