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, 1917-1963, principally comprising official correspondence with Lt Gen M Brocas Burrows, British Military Mission, Moscow, 1944-1945, Gen Mark Wayne Clark, US Army, 1943-1944, 1951-1952, Maj Gen Richard Henry Dewing, UK Army and RAF Liaison Staff, Australia, 1943-1944, Maj Gen Gordon Edward Grimsdale, Military Attaché andhead of Military Mission to Chungking, China, 1942-1943, AF Sir Roger John Brownlow Keyes, Bt, Director of Combined Operations, War Office, 1940-1942, Lt Gen Sir Henry Pownall, South East Asia Command HQ, 1944-1945, Lt Gen Sir Harold Redman, British Joint Staff Mission, Washington DC, 1943-1944, AF Sir James Somerville, Commander-in-Chief Eastern Fleet, 1943-1947, and Maj Gen Sir Edward Spears, Minister to the Lebanon, 1940-1944, and Lt Gen Albert C Wedemeyer, US Army, Deputy Chief of Staff; South East Asia Command, 1944; personal correspondence with and about FM Lord Alanbrooke, 1946-1947, 1957-1963, FM Sir Claude John Eyre Auchinleck, 1941-1961, and FM Archibald Percival Wavell, Viscount Wavell of Cyrenaica and of Winchester, 1943-1946; official andpersonal correspondence with Dwight David Eisenhower, 1942-1965, and AF Louis (Francis Albert Victor Nicholas) Mountbatten, 1st Earl Mountbatten of Burma, 1943-1954, 1960-1964; correspondence with publishers and colleagues, including Gen Sir Richard Nugent O'Connor; papers relating to India, 1947-1951, including his correspondence as Chief of Staff to Mountbatten, 1947, notes on interviews with Jawaharlal Nehru and Mahomed Ali Jinnah, 1947, letters describing the political situation in India, 1947-1948, and correspondence concerning compensation for Indian Government servants, 1948-1951; correspondence concerning the proposed defence reorganisation, 1955-1963; papers relating to his service as Secretary General, NATO (North Atlantic Treaty Organization), 1952-1957, including his official progress reports, 1952-1956; newspaper cuttings, statements to the press and texts of speeches and broadcasts, 1952-1957; papers relating to his memoirs, [1940-1960] including correspondence with publishers, 1960-1961, and colleagues, 1957-1960, notebooks, 1940-1960, and drafts and proofs, [1960]. newspaper cuttings, 1943, 1948, 1951-1952, 1957; texts of speeches, 1943-1958; correspondence relating to operations in Somaliland, 1917-1920; notes and papers relating to his studies at Staff College, Quetta and RAF Staff College, 1922-1924. Papers relating to Rt Hon Sir Winston (Leonard Spencer) Churchill, 1940-1965, including personal correspondence with Churchill, 1940, 1943-1945, 1947-1964; correspondence relating to Churchill's memoir The Second World War (Cassell, London, 1948-1954), 1946-1956, including correspondence relating to Dieppe Raid, Aug 1942, dated 1950, and galley proofs, [1948-1954]. Printed material, 1941-1945, 1947, 1951, notably including copies of telegrams sent by Winston Churchill as Prime Minister, 1941-1942; minutes of Chiefs of Staff meetings, 1943-1944; minutes of Combined Chiefs of Staff meetings, 1943, 1945.