Galen (c. 129 – c. 216 CE) was a prominent Greek physician, surgeon, and philosopher whose medical theories dominated European and Islamic medicine for over a millennium. Born in Pergamon (modern-day Turkey), he studied medicine extensively, combining empirical observation with the prevailing ideas of Hippocrates. Galen served as a physician to Roman gladiators and later to several emperors in Rome, gaining a reputation for his anatomical knowledge and surgical skill. His writings became foundational texts in both medieval European and Islamic medical education. Galen remains one of the most influential figures in the history of medicine.