A proprietress of a laundry in Paris, Catherine Hubscher is known as Madame Sans-Gêne. Among the clients of this carefree woman are Napoléon, a young artillery lieutenant, and Lefebvre, a handsome soldier. After the French Revolution, Napoléon becomes emperor and Lefebvre is appointed a field marshal with the title of Duke of Danzig. Catherine becomes the Duchess of Danzig and alienates Napoléon's sisters by her rough manners at court. Napoléon orders Lefebvre to divorce her but relents when she reminds him of his unpaid laundry bills and of her faithful service to the army during the Revolution.