Finally, the time has come: over the next few years all of Mozart's 26 string quartets will be published by Henle in an Urtext edition of both score and parts. All previous editions have left much to be desired, for example as concerns the correct placement of dynamic markings. Our edition, made with the artistic collaboration of the Armida Quartet, draws upon the large body of modern knowledge concerning Mozart philology and performance practice. We begin with what are, chronologically speaking, the final four quartets: the so-called Hoffmeister Quartet, K. 499, and the three Prussian Quartets, K. 575, 589 and 590. It is possible that the impulse behind the composition of these last three works was the Prussian King Friedrich Wilhelm II, who was an excellent cellist. Modern cellists will find many beautiful melodies to enjoy in them.