Abū Bakr Muhammad ibn Zakariyyā al-Rāzī;
(Persian: ابوبكر محمّد زکرياى رازى Abūbakr Mohammad-e Zakariyyā-ye Rāzī, also known by his Latinized name Rhazes (/ˈrɑːziːz/) or Rasis; 854–925 CE), was a Persian polymath, physician, alchemist, philosopher, and important figure in the history of medicine. He also wrote on logic, astronomy and grammar.
A comprehensive thinker, Razi made fundamental and enduring contributions to various fields, which he recorded in over 200 manuscripts, and is particularly remembered for numerous advances in medicine through his observations and discoveries. An early proponent of experimental medicine, he became a successful doctor, and served as chief physician of Baghdad and Ray hospitals. As a teacher of medicine, he attracted students of all backgrounds and interests and was said to be compassionate and devoted to the service of his patients, whether rich or poor.