Muhammad ibn Zakariya al-Razi was a physician born in al-Ray near Tehran (modern day Iran) in 251 H/ 865 CE. Among his many enduring and fundamental contributions, he was the first physician to detail the symptoms and signs of smallpox and measles and was a pioneer in the use of experimental medicine.

Two of his works “Al-Mansuri” and “Al-Hawi” were used as standard texts for medical students in the Islamic world and throughout Europe for centuries. Edward Granville Browne, a former professor at the University of Cambridge considered al-Razi “probably the greatest and most original of all the Muslim physicians, and one of the most prolific as an author.”