Which composer wrote the piano sonata popularly known as the Moonlight Sonata?

Ludwig van Beethoven wrote the piano sonata popularly known as the Moonlight Sonata.

Its official title is Piano Sonata No. 14 in C-sharp minor, Op. 27 No. 2. Beethoven completed it in 1801, and it was published in 1802 with a dedication to his student, Countess Giulietta Guicciardi.

The nickname “Moonlight Sonata” was not Beethoven’s original title. It became widely used after the German music critic and poet Ludwig Rellstab compared the first movement to moonlight shining over Lake Lucerne. That poetic description appeared several years after Beethoven’s death and gradually became attached to the entire sonata.

The work has three movements. Its famous opening movement, marked Adagio sostenuto, is followed by an Allegretto and a fast, turbulent Presto agitato. The sonata is sometimes mistakenly treated as though “Moonlight” were its formal name, but the nickname is a later popular label.