Ab? Ma'shar, Ja'far ibn Mu?ammad al-Balkh? (also known as al-Falak? or Ibn Balkh?, Latinized as Albumasar, Albusar, or Albuxar) (10 August 787 in Balkh, Khurasan  9 March 886 in W?si?, Iraq), was a Persian astrologer, astronomer, and Islamic philosopher, thought to be the greatest astrologer of the Abbasid court in Baghdad. He was not a major innovator, and his works are practical books for training of astrologers; even as an astrologer he was not intellectually rigorous. Nevertheless, he wrote a number of practical manuals on astrology that profoundly influenced Muslim intellectual history and, through translations, that of western Europe and Byzantium.