The papers cover the period, 1879-1916, and include papers on Howell's service as a correspondent for The Times in the Balkans, including photographs and newspaper cuttings, 1903; papers on Howell's training at Staff College, Quetta, India, and Staff College, Camberley, Surrey, including notes on Cavalry organization and tactics and on the establishment of Frontier Intelligence organization in India, 1904-1914; papers on service as Officer Commanding 4 Hussars, including Operational orders, accounts of Allied operations on Western Front, personal diaries and manuscript maps of Western Front trenches, 1914-1915; Operational orders from service as Brig Gen, General Staff Cavalry Corps, Western Front, 1915; official and semi-official correspondence from service as Chief of Staff, Salonika, including personal diaries, correspondence relating to attempts to secure Bulgarian entry in World War One on the Allied side, and correspondence relating to allegations of Howell leaking memoranda to a Suffragete newspaper called Britannia, 1915-1916. The collection also includes Howell family correspondence, 1879-1889, mostly between Howell's father and grandfather, and from 1909-16 between Howell and his wife Mrs Rosalind 'Linnett' Howell [nee Buxton].

The papers of Howell's wife, Mrs Rosalind 'Linnett' Howell [nee Buxton], 1910-1966, include an account of Howell's life entitled, Philip Howell. A Memoir By His Wife (1942, London, George Allen & Unwin Ltd) and letters from Capt (Edward) Hugh Buxton and Maj (Abbot) Redmond Buxton [Rosalind 'Linnett' Howell's brothers], concerning Allied withdrawal from Anzac Cove and Sulva Bay, Gallipoli, Turkey, 1915-1916.

Papers and photographs relating to Caunter's career, 1908-[1960], including one photograph album, containing 90 photographs, newspaper cuttings and invitations, 1908-1933, notably photographs of Crefeld POW camp, Germany, 1916, Caunter's return to UK following his escape from Schwarmstedt POW camp, Germany, 1917, group photographs of officers, Staff College, Camberley, Surrey, 1922-1923 and Senior Officers Course, Hythe, Kent, 1927, with thirty five loose photographs, 1909-1941, including Salonika, 1918, Iraq, 1920-1921, Egypt, 1936, and Western Desert, Libya, 1941. Papers relating to the First Libyan Campaign, Western Desert, 1940-1941, and Caunter's command of 4 Armoured Bde in the capture of Fort Capuzzo, Battle of Beda Fomm, Libya, Feb 1941, including typescript memorandum by Caunter entitled 'Notes on the disposal of prisoners captured by AFV (Armoured Fighting Vehicle) units', 1 Oct 1940; two typescript 7 Armoured Div intelligence summaries, Dec 1940; typescript memorandum by Caunter entitled 'Some lessons from the campaign', [1941]; typescript account entitled 'The story of the 4th Armoured Brigade in the First Libyan campaign', Western Desert, 1940-1941; two letters from Capt Basil Henry Liddell Hart, dated Jan 1947 and Dec 1951, relating to Caunter's deployment of armoured forces in the Battle of Beda Fomm, Western Desert, Feb 1941. Memoranda and reports relating to Caunter's service as Brig General Staff and Deputy Director of Staff Duties, Armoured Troops, General Headquarters, India, 1941-1943, including typescript memorandum by Caunter, 'Defence of the North West Frontier of India and appreciation' [1942]; typescript report by Lt Col Rothwell H Brown, US Army, 'Report of conditions noted in armoured units and ordnance establishments by the US Army Tank Training Detachment', 10 Nov 1942; edition of Tanks and tank folk by Eric Kennington (Country Life, London, 1943).

Papers, photographs, publications and maps relating to Aston's service as General Staff Officer 2 (Intelligence), 121 Force in Operation IRONCLAD, the British capture, from the Vichy French, of Diego Suarez, Madagascar, May 1942, including typescript intelligence report entitled 'Special report on specified parts of Madagascar', prepared by the Inter Services Topographical Department, 24 Feb 1942, with printed street map of Antsirann, Diego Suarez, and 18 photographs of the topography and infrastructure of Madagascar, 1942; typescript 'Intelligence notes: Madagascar', War Office, 15 Mar 1942; typescript 'Operation IRONCLAD 121 Force operation order No 1', relating to the planned capture, by 121 Force, of Vichy French naval and air base at Thurso Bay, Madagascar, with typescript security instructions, 19 Mar 1942; typescript orders and instructions, landing tables and lists of French military and civilian personnel in Diego Suarez, Apr 1942; typescript memorandum on the interrogation of German prisoners and typescript interrogation reports on Germans and Italians, captured on Madagascar, Jun 1942; printed map of Majunga, Madagascar, annotated with positions of Vichy French defences, Jun 1942; one hundred and eighty eight photographs, some captioned, relating to Madagascar, 1942, notably Maj Gen Robert Grice Sturges, commanding Royal Marines Force, and Brig Francis Wogan Festing, commanding 29 Infantry Bde, Diego Suarez, 12 May 1942; R Adm (Edward) Neville Syfret, Flag Officer commanding Force H, in discussion with French officer, Diego Suarez, May 1942; the British amphibious landings at Tamatave, Sep 1942. Three photograph albums and two autograph books, originally belonging to Aston's stepmother, Sister L A Rowson, Queen Alexandra's Imperial Military Nursing Service (Reserve), containing numerous autographs, poems and illustrations, and 335 photographs relating to Rowson's service in Salonika and Millbank Military Hospital, London, 1915-1919. Publications, photographs and maps relating to World War One, 1914-1918, originally the property of Lt A V Kidman, 513 Field Company, Royal Engineers, including one hundred captioned stereoscopic photographs of World War One, mostly relating to the Western Front, 1914-1918, with stereoscope photograph viewer [1918]; edition of Cavalry training 1912 (HMSO, London, 1916), Field Service Regulations. Part II, Organisation and Administration (HMSO, London, 1916), and Engineer Field Manual (US Government Printing Office, Washington DC, USA, 1917); one printed trench map of Neuville Vitasse, France, May 1918, and one printed map of Belgium and France, Nov 1918. Seventeen, mostly official, publications produced in the UK and France, 1938-1944, notably restricted pamphlets 1-4 of the 'Manual of Military Intelligence in the field', War Office, 1938-1939; four editions of La France Libre, Feb-Jun 1942; The Royal Marines. The Admiralty account of their achievement 1939-1943 (HMSO, London, 1944).