This thesis examines the history and origins of Beethoven's E minor Piano Sonata and examines the possibility of the programmatic conception of the work. Dedicated to Beethoven's friend Count Moritz Lichnowsky, the sonata may have been inspired by the Count's illicit affair with his future wife, the singer and actress Josefa Stummer. Providing a thorough Schenkerian analysis of both movements, the inner harmonic structure of the composition is revealed and explained. The author also investigates and details the unpublished original analyses of the composition by Heinrich Schenker, Erika Elias, and Hans Weisse. Both English and German language sources are incorporated into a comprehensive examination of Beethoven's Piano Sonata, op. 90.