Papers relating to Gallipoli (Faber and Faber, London, 1936), 1927-1967, principally comprising original typescript, [1936]; correspondence, 1927-1967, notably with Brig Gen Cecil Faber Aspinall-Oglander, 1933-1939, Gen Sir Ian (Standish Monteith) Hamilton, 1934-1941, Capt Sir Basil Henry Liddell Hart, 1936-1937, AF Sir Roger John Brownlow Keyes, Bt, 1934-1939, and Maj Gen Arthur Cecil Temperley, 1935-1939; newspaper cuttings, [1915]-1966, including reviews of Gallipoli, 1936-1937, and cuttings relating to the Gallipoli campaign, [1915]-1966; 'Gallipoli', [script of radio programme] by Val Henry Gielgud, 1936; photographs of Gallipoli taken by North, [1936]. Papers relating to North West Europe (HMSO, London, 1953), 1943-1961, including original typescript, [1953]; correspondence, 1944-1957, notably with Liddell Hart, 1953-1954, and FM Bernard Law Montgomery, 1st Viscount Montgomery of Alamein, 1954-1955; press cuttings, 1943-1961, comprising reviews of North West Europe, 1944-1945, dated 1953-1954, and cuttings relating to World War Two, dated 1943-1961; official US Government and HMSO publications relating to World War Two, 1945-1946. Papers relating to The Alexander memoirs (Cassell, London, 1962), dated 1941, 1945, 1946, 1948, 1959-1964, including draft copy, [1962], and published copy, 1962; correspondence, 1961-1964, notably with FM Harold Rupert Leofric George Alexander, 1st Earl Alexander of Tunis, 1961-1963, Liddell Hart, 1961-1962, and Montgomery, 1962; newspaper cuttings, 1945-1946, 1948, 1959-1963; photographs taken by North and Alexander on a visit to the Middle East and Italy, 1960. Other papers, [1931-1968], including articles by North, [1939-1966], notably concerning training, tactics and weaponry; correspondence, [1933-1960]; maps of UK and North West Europe, 1931-1944; press cuttings, 1939-1966, including reviews of Men Fighting (Faber and Faber, London, 1958), 1958-1959; 'Diary of the Belgian Campaign, May 1940', typescript text by AF Sir Roger John Brownlow Keyes, dated [1940].

Typescript draft of 'The memoirs of a professional soldier in peace and war', an unpublished account of Clarke's career in the army, including service in Gallipoli and Palestine during World War One, 1968; various papers and pamphlets collated by Clarke, mainly relating to the training and performance of the Royal West African Frontier Force, 1923-[1960]; articles written by Clarke and published in British and African journals and periodicals, 1926-1959; printer's transparencies of maps used by Clarke in Part Two of the History of the Royal West African Frontier Force (Gale and Polden, Aldershot, 1964).

The papers cover the period 1915-1978, and include papers on his service in World War One, in particular extracts from diary on Galliopoli offensive May 1915 and Allied raid on Zeebrugge, Apr 1918; correspondence, narratives of operations and photographs from service as Officer Commanding Sudan Camel Corps, 1927-1930; reports on defence of British Somaliland and accounts of Italian invasion of Somaliland from service as Officer Commanding Somaliland Camel Corps, 1937-1940; papers on service as Military Governor and Officer Commaning, British Somaliland, 1941-1943; papers on service as Officer Commanding Portsmouth Div Royal Marines, including narrative of Operation OVERLORD, 1943-1944; papers on service as Director of Combined Operations, India and South-East Asia, including notes on Operation LIGHTNING, 1944-1945; papers on service as Commander Chatham Group Royal Marines, including lecture notes1946-1948; unpublished manuscripts on aspects of Allied war effort in British Somaliland; papers on service as Honorary Colonel Somaliland Scouts, 1948-1958, and membership of Anglo-Somali-Society, 1960-1978.

Photographs relating to his naval career, 1912-1949, including photograph album containing photographs taken during his service on HMS BACCHANTE, 1914-1915, at Gallipoli, 1915, and in the North Sea, 1916-1918, Baltic Sea, 1918-1920, East Indies and East Africa, 1921-1924, China Station, 1932-1934, Mediterranean, 1941-1943; photographs of Allied landings at Sword Beach, Normandy, France, 1944. Two volumes of press cuttings relating to the publication of Bless our ship (George Allen and Unwin, London, 1958), 1958, The flowers of the sea (George Allen and Unwin, London, 1962), 1962 and 1971, and Salute the soldier, (George Allen and Unwin, London, 1966), 1966, and Gallipoli (George Allen and Unwin, London, 1975), 1975.