Galen of Pergamon


Born: 129 AD
Died: c.200/c.219 AD
Nationality: Roman/Greek
Famous For: First Experimental Medicine

Galen was a physician and biologist who is referred to as the “father of experimental physiology.” His areas of expertise included physiology, neurology, pathology, logic, philosophy and anatomy. Born Claudius Galenus in Pergamum, his contributions to the knowledge of medicine rank him second only to Hippocrates.

Early Years

Galen’s father was an architect named Aeius Nicon, who made sure that his son had a top-notch education for the time. In his biography, Galen expressed great admiration for his father. Galen studied both Epicurean and Aristotelian philosophy in Pergamum, but after Nicon had a prophetic dream of Aesculapius, the god of medicine, he sent Galen to study medicine. Nicon died when Galen was a young man, but he left him with a fortune that allowed him to follow his studies.


Galen spent at least a decade studying and practicing medicine in Phoenicia, Smyrna, and areas of Greece. He studied anatomy at the famous medical school found in Alexandria, Egypt. When he returned to Pergamum, he was named a surgeon of the gladiators. Given the training gladiators had to undergo and the wounds they suffered, being their surgeon contributed greatly to Galen’s knowledge of health and medicine.

Galen as a Physician

Galen began to have a reputation as a physician and went to Rome. However, he was viewed with jealousy by less skilled physicians. Galen left the city for his own safety but was called back by the emperor Marcus Aurelius. He then became the personal doctor to Commodus, the heir of Marcus Aurelius and later the emperor. Galen was also the court physician to the emperor Septimius Severus. Galen also lectured in the public theaters and performed experiments on animals before crowds. He used animals because dissecting humans had become illegal. The animals he used were mostly pigs and Barbary apes.

The Plague of Galen

During this time, the Plague of Galen struck Rome. Soldiers returning from battle in the Near East were bringing a virus with them that was diagnosed as either smallpox, measles, or something similar. Galen dispassionately recorded the symptoms and prognoses of the victims. That Galen would offer a prognosis for his patients set him apart from the other doctors, who used divination. Galen’s method also caused resentment among his rivals.


Galen was also a very prolific writer and wrote at least 400 books. However, only about 80 of them survive, though they have been translated into many languages. One of the best known books is On the Natural Facilities.

Because Galen was so renowned and considered such an authority, the errors found in the books were considered true by scholars and philosophers until at least the Middle Ages. Indeed, some of his theorems persisted into the Renaissance and even into the 1800s.


Among other things, Galen discovered that arteries contain blood and not air. Before this discovery, people believed that air actually flowed through the arteries. He also knew that the heart pumped the blood, but he never quite figured out how the blood circulated throughout the entire body.


Galen passed away around the year 199 A.D. or 200 A.D. He was about 70 years old, though some sources claim he was a bit older when he died.