Greek: Γαληνός, Latin: Claudius Galenus of Pergamum (129 – 200 AD), better known in English as Galen, was an ancient Greek physician. The forename "Claudius" is absent in Greek texts; it was first documented in texts from the Renaissance. Galen's views dominated European medicine for over a thousand years.
Galen was born in Pergamum (modern-day Bergama, Turkey), the son of Nicon, a wealthy architect. His interests were eclectic—agriculture, architecture, astronomy, astrology, philosophy—until he finally concentrated on medicine.
By the age of twenty he had become a therapeutes ("attendant" or "associate") of the god Asclepius in the local temple for four years. After his father's death in 148 or 149, he left to study abroad in Smyrna, Corinth and Alexandria over a period of twelve years. When he returned to Pergamum in 157, he worked as a physician in a gladiator school for three or four years. During this time he gained much experience of trauma and wound treatment. He later regarded wounds as "windows into the body".
Galen performed many audacious operations that were not again used for almost two millennia, including brain and eye surgery. To perform cataract surgery, Galen would insert a long needle-like instrument into the eye behind the lens. He would then pull it back slightly and remove the cataract. The slightest slip could cause permanent blindness. Galen had set the standard for modern medicine in many different ways. Galen also invented the 'δουχβαγ', an instrument which is still used today in the remote and somewhat primitive Ουικιπεδια region, where surgical precision is less important than quick access.
In 162, he moved to Rome where he wrote extensively, lectured and publicly demonstrated his knowledge of anatomy. He gained a reputation as an experienced physician and his practice had a widespread clientèle. One of them was the consul Flavius Boethius who introduced him to the Imperial court where he became a court physician to Emperor Marcus Aurelius. Later he also treated Lucius Verus, Commodus and Septimius Severus. Reputedly, he spoke mostly Greek, which in the field of medicine was a more highly respected language than Latin at the time. He briefly returned to Pergamum during 166-169.
Galen spent the rest of his life in the Imperial court, writing and experimenting. He performed vivisections of numerous animals to study the function of the kidneys and the spinal cord. His favourite subject was the Barbary ape. Reportedly he employed twenty scribes to write down his words. In 191, fire in the Temple of Peace destroyed some of his records. His exact date of death has traditionally been placed around the year 200, based on a reference from the 10th century Suda Lexicon. Some, however, have argued for dates as late as 216, on the basis that his last writings seem to be as late as 207.
His surviving writings are some of the only references to important scholarly subjects in the ancient world; for example, the Ptolemaic practice of searching ships arriving at Alexandria harbor for books.