Ignaz Joseph Pleyel (1757-1831), a composition student of Josef Haydn, was not only one of the most successful composers of his time, but also an active concert organizer, pianoforte manufacturer, publisher and music dealer. To mark his 250th birthday on 01.06.2007, this critical edition appears on the basis of the text of the first edition stored in the archives of the Schott publishing house. It contains the three most beautiful of the twelve string quartets dedicated by Pleyel to the King of Prussia.