Plutarch was a Greek biographer who lived in the 1st and 2nd centuries AD. He is best known for his Parallel Lives, a series of biographies of famous Greeks and Romans, and his Moralia, a collection of essays and speeches. He also wrote biographies of Alexander the Great and Julius Caesar. Plutarch's works have been highly influential in Western literature and philosophy, and he is considered one of the most important figures in classical antiquity.