Papers and photographs, 1888-1924, 1972, mostly manuscript letters by Simpson-Baikie to his wife, Marion Evelyn Simpson-Baikie, Lady Simpson-Baikie, 1906-1919, including letters whilst on active service on the Western Front, Gallipoli, Salonika and Palestine, 1914-1918; four manuscript letters from Simpson-Baikie to his mother-in-law, Emilita Miller, 1904-1918, and three manuscript letters from Simpson-Baikie to his daughter, Jean Simpson-Baikie, 1917-1918. Also, manuscript letter from Gen Sir Ian Standish Monteith Hamilton to Jean Miller Hamilton, Lady Hamilton, asking her to inform Marion Evelyn Simpson-Baikie that Simpson-Baikie has been chosen to serve at Gallipoli, 1915; manuscript letter to Simpson-Baikie from Gen Sir Horace Lockwood Smith-Dorrien, Governor of Gibraltar, on adverse comments about Smith-Dorrien in 1914 (Spiers, London, 1919) by FM John Denton Pinkstone French, 1st Viscount of Ypres, 1920. Eleven photographs and two negatives relating to Simpson-Baikie's career, 1888-1920, including three photographs of Simpson-Baikie, 1888, [1904]; Lt Gen Horatio Herbert Kitchener, 1st Baron Kitchener of Khartoum, General Officer Commanding in Chief, South Africa, with his Aide de Camp, Lt Francis Aylmer Maxwell [1901]; Maj Gen Hubert Ion Wetherall Hamilton, Maj Gen General Staff, Mediterranean Command, 1911; Gen Sir Ian Standish Monteith Hamilton at Charing Cross station, London, on his departure for Gallipoli, 13 Mar 1915; aerial photograph of the French camp at Sedd el Bahr, Gallipoli, Turkey, 1915. Typescript letter to Jean Morley Kennerley (née Simpson-Baikie) from Professor Robert Clifford Walton concerning Smith-Dorrien, 1972.

Publications, mostly official, relating to UK defence policy, notably, defence expenditure, and equipment procurement, 1960-1990, including ninety-seven editions of House of Commons Official Report. Parliamentary debates (Hansard) (HMSO, London, 1964-1990) and thirteen editions of House of Lords Official Report. Parliamentary debates (Hansard) (HMSO, London, 1975-1990); fifty, mainly UK and USA official printed reports, 1960-1989, including Navy estimates, 1960-1963, Statement on the Defence Estimates (HMSO, London, 1966-1973, 1975-1981, 1988-1989); reports from the House of Commons Defence Committee, 1981-1989; reports relating to specific issues, notably strategic nuclear deterrence, 1973-1982, and the Falklands conflict, 1982-1987. Newspaper cuttings, 1968-1992, mostly relating to Malta, 1968-1972; Soviet seapower in the Mediterranean, 1969-1972; International naval affairs, 1970-1971; South Africa, 1970-1971; the Iran-Iraq War, 1980-1988; the Falklands conflict, 1982; US intervention in Grenada, 1983; Soviet defence policy, 1984-1988; NATO (North Atlantic Treaty Organisation), 1984-1990; UK, US and European defence policy, 1984-1992; the US bombing raid on Libya, 1986; the Gulf War, 1991.