Galen
~130–200 CE · Greek (Roman Empire) · Roman Empire
Known for: Most influential physician in Western history whose theories dominated medicine for 1,300 years
Galen was physician to Roman gladiators and emperors who wrote over 300 medical works. His theories dominated Western and Islamic medicine until Vesalius corrected them 1,400 years later. He was a brilliant observer and writer—but his anatomy was based on animal dissection applied to humans, which introduced systematic errors.
His system of four humors (blood, phlegm, yellow bile, black bile) became medical dogma for over a millennium.
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