Donatien - Alphonse - François de Sade (1740 - 1814), better known as the Marquis de Sade, was a French nobleman and writer. A philosopher and extreme libertine, he wrote erotic narratives about sexual practices that are now known as Sadism. TheMarquis joined the army when he was fourteen and took part in the Seven Years War as acolonel of a cavalry regiment. He wrote most of his works in his confinement due to his scandalous conduct. His works included his famous Justine (1791) and Juliette (1797).