Heroine of Donizetti's opera La Figlia del Reggimento. She first appears as a vivandière or French sutler-girl, for Sulpizio (the sergeant of the 11th regiment of Napoleon's Grand Army) had found her after a battle, and the regiment adopted her as their daughter. Tonio, a Tyrolese, saved her life and fell in love with her, and the regiment agreed to his marriage provided he joined the regiment. Just at this juncture the marchioness of Berkenfield claims Maria as her daughter; the claim is allowed, and the vivandiere is obliged to leave the regiment for the castle of the marchioness. After a time the French regiment takes possession of Berkenfield Castle, and Tonio has risen to the rank of field officer. He claims Maria as his bride, but is told that her mother has promised her hand to the son of a duchess. Maria promises to obey her mother, the marchioness relents, and Tonio becomes the accepted suitor.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894