Die Fledermaus (German: [diː ˈfleːdɐˌmaʊs], The Bat, sometimes called The Revenge of the Bat) is an operetta composed by Johann Strauss II to a German libretto by Karl Haffner and Richard Genée.
The original literary source for Die Fledermaus was Das Gefängnis (The Prison), a farce by German playwright Julius Roderich Benedix that premiered in Berlin in 1851. On 10 September 1872 a three-act French vaudeville play by Henri Meilhac and Ludovic Halévy, Le Réveillon, loosely based on the Benedix farce, opened at the Théâtre du Palais-Royal. Meilhac and Halévy had provided several successful libretti for Offenbach and Le Réveillon later formed the basis for the 1926 silent film So This Is Paris, directed by Ernst Lubitsch.
Meilhac and Halévy's play was soon translated into German by Karl Haffner (1804–1876), at the instigation of Max Steiner, as a non-musical play for production in Vienna. The French custom of a New Year's Eve réveillon, or supper party, was not considered to provide a suitable setting for the Viennese theatre, so it was decided to substitute a ball for the réveillon. Haffner's translation was then passed to the playwright and composer Richard Genée, who had provided some of the lyrics for Strauss's Der Karneval in Rom the year before, and he completed the libretto.