The last novel of the famous Marquis de Sade is the story of the misadventures of the virtuous Princess Adelaide of Brunswick, married to the elderly Prince Frederick of Saxony. In the essay, written at the end of his days, there are no descriptions of either erotic “fantasies” or “disgusting crimes”; the author takes on the role of a defender of virtue, unusual for us. And although the novel is based on an episode from German history of the 11th century, the spirit, the style of the narrative, and many episodes are reminiscent of the 18th century - de Sade was always more interested in the study of human passions than historical verisimilitude.