The Manfred Symphony in B minor, Op. 58, is a programmatic symphony composed by Pyotr Ilyich Tchaikovsky between May and September 1885. It is based on the poem "Manfred" written by Lord Byron in 1817. It is the only one of Tchaikovsky's symphonies he completed that is not numbered (the Symphony in E flat is a conjectural work left unfinished by the composer) and was written between the Fourth and Fifth Symphonies.
Like the fantasy-overture Romeo and Juliet, Tchaikovsky wrote the Manfred Symphony at the behest of the nationalist composer Mily Balakirev, who provided a program written by critic Vladimir Stasov. Stasov had sent the program to Balakirev in 1868, hoping that Balakirev would write a symphony based on it. Balakirev did not feel capable of carrying out this project and sent the program to the French composer Hector Berlioz, whose programmatic works had genuinely impressed him. Berlioz refused, claiming old age and ill health, and returned the program to Balakirev. Balakirev kept the program until he reestablished contact with Tchaikovsky in the early 1880s.
The Manfred Symphony is the only programmatic symphonic work by Tchaikovsky in more than one movement. He initially considered the work one of his best, and in a typical reversal of opinion later considered destroying all but the opening movement. The symphony was greeted with mixed reviews, some finding much to laud in it, and others feeling that its programmatic aspects only weakened it. Manfred remained rarely performed for many years, due to its length and complexity. It has been recorded with increasing frequency but is still seldom heard in the concert hall.
In the first ten years after graduating from the Saint Petersburg Conservatory in 1865 Tchaikovsky completed three symphonies. After that he started five more symphony projects, four of which led to a completed symphony premiered during the composer's lifetime.