This collection consists primarily of the correspondence received by Harold Nicolson from friends and colleagues, as well as a large series of letters written by Nicolson to Richard Rumbold, and a few to others (1917-1962). Much of the correspondence is from various British and European statesmen, British and French authors, and other public figures, such as Maurice Baring, Clive Bell, Bernard Berenson, Guy Burgess, Anthony Eden, Earl of Avon, Sir John Gielgud, John Gunther, Francis King, Alan Lascelles, Charles A. Lindbergh, André Maurois, Paul Morand, Raymond Mortimer, Robert Vansittart, and H. G. Wells. There is also a small selection of miscellaneous material, including a menu signed by the British delegation to the Paris Peace Conference in 1919.

Also included in the collection are three manuscripts by Nicolson, Benjamin Constant (1949), Journey to Java (1957), and Paul Verlaine (1921), and a set of working notes for Sainte-Beuve (1957). The Sainte-Beuve material is the only existing example of Nicolson's working notes, while the manuscripts are some of only a few to survive (together with Tennyson: Aspects of His Life, Character and Poetry which is on display at Sissinghurt Castle, and Public Faces: A Novel which was sold at auction).

Furthermore, there are a small amount of papers of others, chiefly correspondence by and to Nicolson's wife, "Vita" (Victoria) Sackville-West, with Raymond Mortimer and Richard Rumbold.

All the letters identified in this listing are signed autographed letters unless otherwise indicated (ACS = autograph card signed, TLS = typed letter signed).