Fidelio is an opera in two acts by Ludwig van Beethoven. It is Beethoven's only opera. The German libretto is by Joseph Sonnleithner based on a French story. The opera tells how Leonore, disguised as a prison guard called "Fidelio", rescues her husband Florestan from death in a political prison.
Fidelio is an example of a “rescue opera”, a type of opera which was popular at the time. The hero (or heroine) has to fight against cruel people in order to rescue a lover. It was written at the time of the French Revolution. At this time, ideas about freedom and peace were being talked about by everyone, and this led to wars all over Europe. The famous Prisoners’ Chorus is a song for freedom, just like the last movement of his Ninth Symphony.
Beethoven spent some time working on the opera before he was completely happy with it. The first time it was performed (in 1805) it was a three-act opera called Leonore. There were a lot of French military officers in the audience and they thought they were being criticised. In 1806 it was performed again with two acts and a new overture (now known as "Overture: Leonore No. 3"). But arguments between Beethoven and the theatre management meant there were no more performances. Eight years later Beethoven revised his opera again. This time it was called Fidelio, and it was a great success. It has remained a famous opera ever since.