The Op. 50 string quartets contain some of the purest writing Haydn ever accomplished. In this first full account of the six quartets, Dean Sutcliffe evaluates the Op. 50 in relation to Haydn's more frequently performed quartets and considers their relevance to Haydn's wider output. Each quartet is discussed in detail. The background to these works includes a brief history of the string quartet and an assessment of Haydn's earlier works in this genre and of his role at Esterhaza. The description of the composition and publication of the Op. 50 quartets is based on the evidence of Haydn's surviving letters and the recently discovered autograph copies of nos. 3 to 6--a discovery that is vividly documented here for the first time.