The composer of the famous Moonlight Sonata is...

Beethoven! Beethoven composed the famous Moonlight Sonata in 1801, and dedicated it to Countess Giulietta Guicciardi, one of his pupils. Shortly after their first few lessons, the two fell in love. After dedicating the "Moonlight" Sonata, it is believed that Beethoven proposed to her. Although she was willing to accept Beethoven’s proposal, forbiddance by one of her parents prevented her from marrying him. Learn more about the Moonlight Sonata.