The Piano Sonata No. 14 in C-sharp minor "Quasi una fantasia" by Ludwig van Beethoven, is popularly known as the "Moonlight" Sonata. The work was completed in 1801 and dedicated to his pupil, 17-year-old Countess Giulietta Guicciardi, with whom Beethoven was, or had been in love. The name "Moonlight" Sonata derives from an 1832 description of the first movement by poet Ludwig Rellstab, who compared it to moonlight shining upon Lake Lucerne.
