The collection consists of:
1. Papers concerning Colonel James Duff (1820-1898). These papers (three items only, 1966-1967 and [ca.1964-1970]) include a transcript of sixteen letters written by Colonel Duff while serving as an ensign with the 74th Highlanders in Canada 1841-1845 and a memoir of him by his grandson Alan Colquhoun Duff.
2. Papers of James Duff Duff (1860-1940). These papers (53 items, 1871-1923, [ca.1946-1956] and [ca.1964-1973]) chiefly consist of correspondence, press cuttings etc. relating to his publications. They include four letters of 1904, 1911 and 1923 and one paper of 1923 from A.E. Housman and a letter of 1916 from Edmund Gosse. There is also a memoir of James Duff Duff by [his son Alan Colquhoun Duff].
3. Papers of Sir James Fitzjames Duff (1898-1970). These comprise the bulk of the collection. They were heavily weeded before their deposit with the University of Durham to remove any material which might be thought sensitive or confidential, but, as well as family material, contain a series of papers relating to Duff and his career, -1967, correspondence addressed to him, volumes (including diaries, journals, lecture and teaching notes and notes relating to universities in Canada and the United States of America), some photographs, a medallion and patents of appointment, and printed material, mainly consisting of his own publications, but also including intelligence test material, some of it annotated, [?1919]-1936. The BBC and lord lieutenancy material is almost exclusively photographic.