The collection covers Pyman's career from 1937 until 1963 when he suffered a severe stroke which forced his retirement in 1964. The earliest papers date from Pyman's work with the Royal Tank Cadre in converting the 17/21 Lancers from a cavalry to an armoured regiment. There are also papers from Pyman's period as an instructor at the Staff College in Quetta, India, 1939-1941. Pyman was involved in the World War Two campaigns by the 8 Army in the Western Desert, in 1941 as General Staff Officer with 7 Armoured Div, 30 Corps and in 1942-1943 as Commander of the 3 Royal Tank Regiment, 10 Armoured Div, 30 Corps. The papers consist mostly of Pyman's assessments of lessons learned from the ongoing campaigns particularly with regard to tanks and armoured units. In 1944-1945 Pyman was Brigidier General Staff, 30 Corps, 2 Army in the Normandy landings and the invasion of Northern Europe, with particular responsibility for organisation and planning of the Rhine crossing and advance to the Baltic. This is reflected in the papers which largely consist of planning studies and reports for the operations involved, this section also contains maps used in the campaign. Pyman's next appointment was as Chief of General Staff, Allied Land Forces, South East Asia, 1945-1946 which is documented by a series of diaries which reflect the tasks faced by Pyman in this command including dealing with the build up of tension between newly liberated former colonies keen to assert their right for independence and the former colonial powers such as France and Netherlands. Pyman spent 1946-1949 as Chief of Staff, Middle East Land Forces and kept monthly diaries which form the bulk of this section of the collection. The diary entries and additional papers reflect the debate over policy in the Middle East in the British Government and Military command, they include detail on the British withdrawal from Greece, the problem of illegal Jewish immigrants and their internment in Cyprus, the end of the British mandate in Palestine and the the effect of this on relations between Britain with Egypt and the other Arab states and the subsequent Arab Israeli conflict. This section of the collection also contains correspondence between Pyman and Maj Gen Sir Miles Christopher Dempsey on personal matters and on the Middle East. There are also papers from Pyman's work at the Ministry of Supply as Director General of Fighting Vehicles, 1951-1953, Director of Weapons Development, War Office, 1955-1956 mostly brief diary entries and lecture texts. Pyman was also General Officer Commanding, British Army on the Rhine, 1953-1955 and General Officer Commanding, 1 British Corps, 1956-1958 and the papers relating to these commands consist mostly of lectures, reports and directives reflecting his interest in armoured divisions and training. There are some papers, mostly personal correspondence and press cuttings, from Pyman's final command as Commander-in-Chief Allied Forces Northern Europe in North Atlantic Treaty Organisation (NATO). The collection also contains correspondence relating to Pyman's role as Colonel Commandant of the Royal Tank Regiment and The Royal Armoured Corps and a series of letters covering the reorganisation of the Berks and Westminster Dragoons, of which he was Honorary Colonel. The rest of the collection consists of diaries, correspondence, speeches, writings including the draft copy and papers relating to his autobiography, some preparatory work on a history of the 2 Army and reference works. The collection also includes the Boer War diaries and other papers of Col James Redmond Patrick Gordon who commanded the 1 Cavalry Bde of the South African Field Force 1900-1901 which were given to Pyman by a friend.

Papers relating to his life and career, 1915-1991, dated 1963, 1969 and [1991], principally comprising 'Nine lives, a soldier's story', a typescript memoir covering the period 1915-1991, including his service in North Africa and the Western Desert, 1939-1942 and 1943, the Middle East, 1942-1943 and 1954-1956, Normandy, 1944, and France, Belgium and Germany, 1945-1947, and hiswork as Director General of Fighting Vehicles, 1964-1966, and General Officer Commanding, Malta and Libya, 1967-1968, written in [1991].

Papers of Maj Gen Ian Helstrip Baker, notably concerning armoured warfare, 1955-2003, including instructions, memoranda, reports and notes on training exercises including Exercise GAMEBIRD, Cyclops Sqn, 2 Royal Tank Regt, Libya, Jul 1964; Exercises OPEN GLOVE and TREBLE CHANCE, Cyclops Sqn, 2 Royal Tank Regt and 16 Parachute Bde Group, Sep 1964; Exercise DOUBLE STRETCH 72, 7 Armoured Bde, Germany, Feb-Mar 1972; Exercise RED RAT, 7 Armoured Bde, Germany, Sep-Oct 1972; MACLEOD, 7 Armoured Bde, Germany, Aug-Sep 1972; Exercise READY RAT, 7 Armoured Bde, Germany, 11 Sep 1972; Exercise LONG LOOK, for 7 Armoured Bde trials of ZB298 radar, Oct 1971-Apr 1972; organisational trial Exercise SQUARE RAT, Germany, 28 Dec 1972; Exercise FIRST STRETCH 73, 7 Armoured Bde, Germany, Feb 1973; Exercise DOUBLE STRETCH 73, 1 Armoured Bde, Germany, Mar-Apr 1973; Exercise HURST PARK 73, 7 Armoured Bde, Germany, Apr 1973; Exercise QUEEN'S PATROL, 7 Armoured Bde, Germany (relating to operations in Northern Ireland), May 1973; Exercise RED RAT 73, 7 Armoured Bde, Germany, Aug 1973; Exercise FOUR SQUARE, 7 Armoured Bde, Germany, Sep-Nov, 1973; photographs of [FV214 Conqueror battle tanks], Royal Armoured Corps, Bovington, Dorset and photograph of an amphibious jeep, partially submerged, 1960; photograph of Crown Prince Birendra of Nepal and others watching a Hornet Launcher vehicle being loaded with Malkara missiles by personnel of Cyclops Sqn, 2 Royal Tank Regt, Candahar Barracks, Tidworth, 15 Apr 1964; captioned photographs relating to Baker's visit to [1 Bn, Royal Green Jackets], Belfast, Northern Ireland, including: battalion personnel on patrol; Falls Road and Hamilton Street, Belfast, showing the aftermath of explosions; IRA weapons discovered, including rifles, knives, an RPG7 rocket launcher and RPG7 rockets, a car bomb and smaller incendiary devices, Aug 1972; photographs of Baker, Nov 1979 and in Brigadier's uniform; handing over briefing notes by Baker as Deputy Assistant Adjutant General, 17 Gurkha Div, Overseas Commonwealth Land Forces, 25 Jun 1962; training instructions for Cyclops Sqn, 2 Royal Tank Regt, Tidworth, Mar 1963-May 1964; briefing notes on the Parachute Sqn, Royal Armoured Corps, by Baker, 1964; Royal Armoured Corps training pamphlet, 'The technique of shooting from AFVs. Part 4: the application of fire from Saladin armoured cars' (MoD, Feb 1967); 1 Royal Tank Regt standing operational procedures, Jun 1969; briefing notes for Baker as Commander, 7 Armoured Bde, by Administration and Quartering staff, 7 Armoured Bde, 18 Jan 1972 and by Brigade Majors, 7 Armoured Bde, 7 Feb 1972; 7 Armoured Bde standing operating procedures relating to headquarters and operations (vol. 1), and administration and logistics (vol. 2), Feb 1972; training directives by Baker as Brigadier Commanding 7 Armoured Bde, Mar-Sep 1972; notes on the creation and history of the Desert Rat badge of 7 Armoured Bde, 1940-1972; training directive by Baker as Brigadier Commanding 7 Armoured Bde, Mar 1973; correspondence and accounts by Lt Col R A Pascoe, 1 Bn Royal Green Jackets, of the battalion's service in Belfast, 8-14 Oct 1972.