Julie ("Giulietta") Guicciardi (23 November 1782 – 22 March 1856) was an Austrian countess and briefly a piano student of Ludwig van Beethoven. He dedicated his Piano Sonata No. 14 to her, which is now commonly known as the Moonlight Sonata. (Wikipedia)

Julie Guicciardi, as she was named by her family, was born in Przemyśl, Galicia in 1782. She arrived in Vienna with her parents from Trieste in June 1800, and her beauty caused her to be noticed by high society. She was soon engaged to Count von Gallenberg (1780–1839), an amateur composer, whom she married on 14 November 1803. Subsequently, they moved to Naples, and she continued to live in Italy for some 20 years. In later years, Count Hermann von Pückler-Muskau was among her admirers.

Beethoven widmete die Sonate später seiner damals 20-jährigen Klavierschülerin Gräfin Julie Guicciardi (1782–1856), in die er zuvor für kurze Zeit verliebt gewesen war.

https://de.wikipedia.org/wiki/Giulietta_Guicciardi