Joseph Fouché encounters Charlotte de Robespierre while he works as a teacher at the Oratorian College in Arras and the two come to an understanding, which Fouché later breaks off. He becomes a Jacobin and a deputy in the National Convention. After the events in this novel, Fouché becomes a significant figure in French governments to follow.
Joseph Fouché | French statesman | Britannica
Joseph Fouché - Wikipedia