Youngest sister of Louis XVI (1764-1794), commonly known as “Madame Elisabeth,” who, with most of her family, was executed during the Reign of Terror. ALS in French signed “Elisabeth,” one page, 4 x 6, [dated in pencil in another hand] July 20, 1788. An untranslated letter mentioning a royal appointment. Accompanied by an antique portrait engraving. Light intersecting folds (horizontal fold lightly touching signature) and a touch of mild wrinkling, otherwise fine condition. R&R COA.