Abū Bakr al-Rāzī, also known as Rhazes, was a Persian Muslim physician, philosopher, alchemist, and pre-eminent medical writer of the Islamic Golden Age, widely regarded as one of the most important figures in the history of medicine. In addition to medicine and philosophy, he wrote on logic, astronomy, and grammar. 854 – 925; died at about 71. Alive at the same time as Alfred the Great, Farabi, Rudaki, Al-Kindi, and Charles the Bald. Wiki link