 While there, Beethoven met the King of Prussia Friedrich Wilhelm II, an ardent music-lover and keen cellist.Although the sonatas are dedicated to Friedrich Wilhelm II, Ferdinand Ries tells us that Beethoven "played several times at the court, where he also played the two cello sonatas, opus 5, composed for Duport (the King's first cellist) and himself".Although Jean-Pierre Duport was one of the King's teachers, it is now thought to have been his brother Jean-Louis Duport who had the honor of premiering these sonatas.