Letters from Marshall to his brother, John Eden Marshall (1864-1937), the Hon Mr Justice Marshall, Judge in Egyptian Court of Appeal, written throughout World War One, including chatty, if brief, descriptions of his service in Gallipoli, Salonika and Mesopotamia, where he became Commander in Chief of the Mesopotamian Expeditionary Force in Nov 1917, 1915-1919. The great bulk of the letters are therefore written from Mesopotamia, 1916-1919, and include Marshall's descriptions of the second Battle of Kut el Amara, Dec 1916; the advance to and the fall of Baghdad, Mar 1917, with impressions of the city; the Battle of Band-i-Adhaim, 30 Apr 1917; the building of railways and improvement of communications along the British front line; commentary on the progress of the war on the Western, Eastern and Southern fronts; commentary on the progress of the British forces under Gen Sir Edmund Henry Hynman Allenby on the Palestine front, 1917-1919; the clearance of Jebel Hamrin and the River Diyala, Mesopotamia, Oct 1917; the 'Dunsterforce' operation in Persia, 1918; the advance up the Euphrates and the taking of Hit and Khan Baghdadi, Mar-May 1918; the final offensive on the Tigris, Oct-Nov 1918, culminating in the signing of an armistice with the Turks on 30 Oct, 1918.

Copies of papers relating to his military service, 1898-1945, dated 1917 and [1945], comprising a letter to his wife describing the fall of Baghdad, 10 Mar 1917, and subsequent conditions in the city, dated 16-17 March 1917; official Mesopotamian Expeditionary Force General HQ 'Despatch on operations', 28 Aug 1916-31 Mar 1917, dated Apr 1917; summary of his military service, 1898-1945, written in [1945].

Pre-war papers and correspondence, 1898-1914, including lectures, texts and notes written whilst Commandant of the Staff College, Camberley, Surrey. Papers relating to his service as Quartermaster General to the BEF (British Expeditionary Force), Western Front, 1914-1915, including correspondence with Maj Gen Sir Stanley Brenton von Donop, Master General of the Ordnance, and Maj Gen Sir John Steven Cowans, Quartermaster General to the Forces, relating to supplies of equipment, provisions and munitions. Papers and correspondence, 1915, as Chief of General Staff, BEF (British Expeditionary Force), Western Front, principally comprising reports and memoranda prepared for the War Office and the War Council by General Headquarters Staff, 1915; memoranda relating to general military strategy, 1915, notably in the Balkans, Dardanelles, Gallipoli and Egypt; papers in French concerning the Allied Conference at Chantilly, 1915. Papers relating to service as Chief of the Imperial General Staff during World War One, 1915- 1918, principally comprising Army Council and War Cabinet papers relating to manpower, 1915-1918; papers of FM Horatio Herbert Kitchener, 1st Earl Kitchener of Khartoum and Broome, Secretary of State for War, given to Robertson following Kitchener's death in Jun 1916; personal telegrams, 1916- 1917, mainly comprising unofficial messages to and from various army commanders and military attachés in Salonika, Russia, Egypt, Mesopotamia, Italy, Romania, Palestine and the Western Front; memoranda and papers on military operations in the Middle East, 1915-1917, and general strategy, 1917-1918, prepared by Robertson for the War Cabinet; documents relating to the creation of the Allied Supreme War Council, and its various powers and functions, 1917-1918. Papers created as Commander in Chief, Eastern Command and Home Forces, 1918-1919, consisting of inspection reports of various depots and units in the UK, and general correspondence. Papers created as General Officer Commanding in Chief, BAOR (British Army of the Rhine), 1919-1920, including printed memoranda by French Marshal Ferdinand Foch, Allied Supreme Commander on the Western and Italian Fronts, on the conditions required to ensure peace in Europe, 1918-1919; papers relating to the organisation and functions of the British Zone of Occupation in Germany, 1919; correspondence with Gen Sir Henry Hughes Wilson, Chief of the Imperial General Staff, the Rt Hon Winston (Leonard Spencer) Churchill, Secretary of State for War, and Maj Gen Sir Charles 'Tim' Harington Harington, Deputy Chief of the Imperial General Staff, 1919; inspection reports of BAOR (British Army of the Rhine) units, 1919. Private correspondence, mainly relating to Robertson's work during World War One, including correspondence with Lt Col Arthur John Bigge, 1st Baron Stamfordham, Private Secretary to HM King George V, 1914-1918; Maj Gen Charles Edward Callwell, Director of Military Operations at the War Office, 1915; Gen Sir Archibald (James) Murray, Chief of the Imperial General Staff and General Officer Commanding in Chief, Egyptian Expeditionary Force, 1915-1916; the Rt Hon David Lloyd George, Secretary of State for War, 1916, and Prime Minister, 1916-1918; FM Sir Douglas Haig, Commander in Chief, British Armies in France, 1915-1918; Maj Gen Frederick (Barton) Maurice, Director of Military Operations at the War Office, 1917-1918; and the Rt Hon Winston (Leonard Spencer) Churchill, Secretary of State for War, 1919-1920. Also including correspondence, memoranda and notes concerning the events leading up to the resignation of Robertson as Chief of the Imperial General Staff in Feb 1918, dated Jan-Feb 1918. Semi-official papers and private correspondence, 1915-1918, collected by Brig Gen Cecil Courtenay Lucas, Robertson's Aide de Camp, mainly comprising correspondence between Robertson and Gen Sir Archibald (James) Murray, Gen Sir Beauchamp Duff, Gen Sir Charles Carmichael Monro, and Gen Sir Edward Henry Hynman Allenby, relating to military operations in India, Mesopotamia, Egypt and Palestine, 1916-1918; Lt Col Sir Maurice Pascal Alers Hankey, Secretary to the War Cabinet and the Committee of Imperial Defence, 1916-1917; Lt Gen the Rt Hon Jan Christian Smuts, South African Representative on the British War Cabinet, 1917; Gen Sir (Francis) Reginald Wingate, Governor General of the Sudan, 1916, and High Commissioner of Egypt, 1917; and Lt Col Charles A'Court Repington, Military Correspondent of The Times, 1916-1917. General correspondence with various on military matters, 1916-1918, including Reginald Baliol Brett, 2nd Viscount Esher, Lt Gen George Francis Milne, French Gen Robert Georges Nivelle, Italian Gen Luigi Cadorna, Lt Gen Sir Frederick Stanley Maude, and Gen Sir Herbert Charles Onslow Plumer.

Papers, 1899-1937, and 1964-1966, including personal letters to Alice Townshend, Lady Townshend, and to Comtesse Cahen d'Anvers from FM Horatio Herbert Kitchener, 1st Earl Kitchener of Khartoum and Broome, 1906-1911, also single personal letters from Frederick Edward Grey Ponsonby, Assistant Private Secretary to Queen Victoria, 1899, FM Garnet Joseph Wolseley, 1st Viscount Wolseley, 1901, Brig Gen Sir William Riddell Birdwood, Bt, 1906, Christian Rudolf de Wet, Minister of Agriculture, Orange River Colony, South Africa, 1909, FM Frederick Sleigh Roberts, 1st Earl Roberts of Kandahar, Pretoria and Waterford, 1911-1912, Rt Hon George Nathanial Curzon, Lord Privy Seal, 1915, Rt Hon Herbert Henry Asquith, Prime Minister, 1916, Paul Cambon, French Ambassador to Court of St James's, 1916, Lt Gen Sir Philip Walhouse Chetwode, 7th Bt, Military Secretary, War Office, 1919, and others; letter from Alice Townshend, Lady Townshend, dated 1916, to Mrs Morland, mother of Capt Walter Edward Thomson Morland, Aide de Camp to Townshend and captured with him at Kut el Amara, Mesopotamia, with information on the safety of her son, with three photographs of Townshend and the POW accomodation in Constantinople, 1916; scrapbook of newspaper cuttings, 1916, on the Mesopotamian campaign and the defence and siege of Kut el Amara, with signed printed portrait of Mustafa Kemal Atatürk, 1937; file of research correspondence by Lt Col Arthur James Barker for The neglected war (Faber, London, 1967) and Townshend of Kut (Cassell, London, 1967), 1964-1966, including correspondence with Capt Sir (Thomas) Noël Arkell, FM Sir Claude John Eyre Auchinleck, Maj Gen George Osborne de Renzy Channer, Sir Reader (William) Bullard, Brig Kenneth Bredin Shakespear Crawford, Sir Ernest (William) Goodale, Capt Basil Henry Liddell Hart, Maj Gen Henry Hampden Rich, Col Clive Woodes Rogers, Col Eric Lechmere Stephenson, Countess Audrey de Borchgrave-Townshend, Brig Louis James Woodhouse.