Fidelio abandoned "Vestas Feuer" for "Fidelio", and was eventually freed from his obligations to Schikaneder when the latter was fired from his post as theater director in 1804. "Fidelio" itself, which Beethoven began in 1804 immediately after giving up on "Vestas Feuer", was first performed in 1805 and was extensively revised by the composer for subsequent performances in 1806 and 1814. Although Beethoven used the title ' ("Leonore, or The Triumph of Married Love"), the 1805 performances were billed as "Fidelio" at the theatre's insistence, to avoid confusion with the 1798 opera ' by Pierre Gaveaux, and the 1804 opera "Leonora"
Fidelio a rival nobleman, Pizarro. In revenge, Pizarro has secretly imprisoned Florestan in the prison over which he is governor. Simultaneously, Pizarro has spread false rumors about Florestan's death. The warden of the prison, Rocco, has a daughter, Marzelline, and an assistant, Jaquino, who is in love with Marzelline. The faithful wife of Florestan, Leonore, suspects that her husband is still alive. Disguised as a boy, under the alias "Fidelio", she gains employment working for Rocco. As the boy Fidelio, she earns the favor of her employer, Rocco, and also the affections of his daughter Marzelline, much to Jaquino's chagrin. On