Pietro Aretino has been termed the "greatest erotic writer in Christendom." Perhaps his most famous work is the "Ragionamenti", partly biographical. Aretino was active as a writer for more than forty years, during which time he produced poetry and pornography, plays and theological works, lives of the saints and lampoons on the living. He was a friend of Michelangelo and Titian. He talked with popes. He has been depicted as "the Renaissance counterpart of Petronius in the ancient world, or of the Marquis de Sade in the period of European revolution."