The occupying French garrison is commanded by a young officer named Victor Marchand, and he is in love with Clara, the daughter of Marquis Léganès, who is the local grandee.
One night under cover of a local festival, there is an uprising against the French garrison, supported by British naval ships.
Marquis Léganès asks the general, that he and his family be executed by beheading rather than hanging, and that his eldest son should be spared.
The King of Spain has given him the title of El Verdugo (the Executioner), but in his grief and guilt, Juanito shuns society.
However, El Verdugo is one of a number of works from other parts of La Comedie humaine along with Le Médecin de campagne, Adieu and others which depict military scenes from the Revolutionary and Napoleonic Wars.