 The Abbasid Caliphate in Baghdad underwent extreme intellectual and medical experimentation during the 10th and 11th centuries.Among the many skilled physicians and intellectuals there was Abū Bakr Muḥammad ibn Zakariyyāʾ al-Rāzī, or in Latin, Rhazes (854–925).Rhazes served as chief physician in a hospital in Rayy, Iran, before holding a similar position in the Baghdad hospital.