135, by Ludwig van Beethoven was written in October 1826[1] and was the last major work he completed.

Beethoven dedicated the composition to his patron and admirer, Johann Nepomuk Wolfmayer.

The Schuppanzigh Quartet premiered the work on 23 March 1828, one year after Beethoven's death.

Under the introductory slow chords in the last movement, which is headed Der schwer gefaßte Entschluß (The difficult decision), Beethoven wrote in the manuscript Muß es sein?

The work features in Czech author Milan Kundera's The Unbearable Lightness of Being, where the character Tomas uses the phrases Muß es sein?