La fille du régiment (The Daughter of the Regiment) is an opéra comique in two acts composed by Gaetano Donizetti during his stay in Paris, between 1838 and 1940. Its libretto was written by Jules-Henri Vernoy de Saint-Georges and Jean-François Bayard. Its first performance took place on 11 February 1840 by the Paris Opéra-Comique at the Salle de la Bourse. The opera quickly became a popular success, partly because of the famous aria "Ah! mes amis, quel jour de fête!", which requires of the tenor no fewer than nine high Cs.
