War and Peace (Op. 91) (Russian: Война и мир, Voyna i mir) is an opera in two parts (an Epigraph and 13 scenes), sometimes arranged as five acts, by Sergei Prokofiev to a Russian libretto by the composer and Mira Mendelson, based on the novel War and Peace by Leo Tolstoy. Although Tolstoy's work is classified as a novel, the 1812 invasion of Russia by the French was based on real-life events, and some real-life people appear as characters in both the novel and the opera, e.g. Prince Mikhail Kutuzov and Napoleon Bonaparte.

Librettist Sergei Prokofiev and Mira Mendelsohn (Based on the novel "War and Peace" by Leo Tolstoy)
Date of composition 1943 (1941-1943. Revised in 1946-1952)
Premiered 1945, June 7th (Great Hall of the Moscow Conservatory) in Moscow, Russia
Type Opera
Catalogue Op. 91
Approx. duration 120 minutes
Spoken language Russian
Instruments Voice (Soprano) - Natalya (Natasha) Rostova
Voice (Tenor) - Count Pyotr (Pierre) Bezukhov
Voice (Baritone) - Prince Andrei Bolkonsky
Voice (Bass) - Field-Marshal Prince Mikhail Kutuzov
Voice (Baritone) - Napoleon Bonaparte
Voice (Bass) - Count Ilya Rostov, Natasha's father
Voice (Mezzo-Soprano) - Hélène Bezukhova, Pierre's wife
Voice (Tenor) - Prince Anatole Kuragin, Hélène's brother
Orchestra
Arrangements Sergei Prokofiev: Three Transcriptions for Piano (from War and Peace and Lermontov), Op. 96
Autotranslations beta Sergueï Prokofiev: War and Peace, Op. 91
Sergej Sergeevič Prokof'ev: War and Peace, Op. 91
Sergei Sergejewitsch Prokofjew: War and Peace, Op. 91