The Cello sonata no. 1 (Op. 5/1) was written by Beethoven in 1796, while in Berlin. It was written together with the 2nd sonata. He composed the pieces for the cellist king Friedrich Wilhelm II of Prussia, and played them several times in court. In the early 19th century, sonatas for piano and instrument were advertised as piano sonatas with instrumental accompaniment. The cello sonata was especially so, as it grew out of sonatas for continuo; as late as the beginning of the 19th century it was still common for the cello in cello sonatas to double the left hand of the piano part. Beethoven is credited with composing the first cello sonatas with a written-out piano part.
