‘A shadowy entity’: M.I.1(b) and British Communications Intelligence, 1914–1922^*

* All ADM, CO, FO, HS, HW, T and WO references are from The (UK) National Archives; IOR references are from the India Office records in the British Library; IWM references are from the Imperial War Museum; NARA references are from the (US) National Archives and Records Administration.

Abstract

Although the part played by the British War Office’s cryptanalytic bureau in diplomatic cryptanalysis during the First World War is better understood than formerly, its contribution to military Communications Intelligence (Comint) has remained largely unknown. This article describes the origins of what eventually became M.I.1(b), its wartime development as a military cryptanalytic (and eventually cryptologic) bureau, and its post-war demise; it also seeks to identify the factors that contributed to its subsequent obscurity. It concludes that M.I.1(b) played a key role in British army Comint during the First World War, both through its own cryptanalytic work and in supporting and coordinating the efforts of widely dispersed field cryptanalytic activities, and that its subsequent obscurity has served to distort understanding of the development of British Comint.

Acknowledgements

This article was inspired by numerous discussions of British Sigint in the First World War with the late Peter Freeman. I am grateful to Professor John Ferris, Doctor Jim Beach and the GCHQ Departmental Historian for their comments at various stages in the evolution of this piece.

Notes

* All ADM, CO, FO, HS, HW, T and WO references are from The (UK) National Archives; IOR references are from the India Office records in the British Library; IWM references are from the Imperial War Museum; NARA references are from the (US) National Archives and Records Administration.

1. Cork Street Book, Hay Papers, Aberdeen University, Department of Special Collections and Archives.

2. Ferris, “Road to Bletchley Park,” 55, 59.

3. For the general development of British diplomatic Comint see Freeman, “M.I.1(b),” 206–28; for a particular application see Larsen, “Colonel House,” 682–704.

4. Seligmann, “Hors de Combat?,” 52–8.

5. ‘Room 40 OB war diary and logbook M05E’ [sic], ADM 223/767 (hereafter ‘M.O.5(e) War Diary’), despite the catalogue description this is purely the diary of M.O.5(e); working papers in HW3/184, 3/185 and 3/186; ‘History of M.I.1(b)’, War Office, HW7/35, n.d. but almost certainly the 1920 history of M.I.1(b) by Major Brooke-Hunt cited in ‘Note on the division of responsibility between the War Office and the GC&CS’, M.I.1(b), 21 July 1932, HW62/19 (hereafter ‘History of M.I.1(b)’).

6. ‘Historical Sketch of the Directorate of Military Intelligence during the Great War, 1914–1919’, War Office, 1921, WO32/10776 (hereafter ‘Historical Sketch’); ‘The History of the Development of the Directorate of Military Intelligence 1855–1939’, War Office, 1957, WO106/6083 (hereafter ‘Development of DMI’); War Office, annual War Office List and aperiodic Allocation of Rooms with Lists of Officials employed in the War Office (hereafter ‘Lists’); officers’ personal files, WO339 and 374; curricula vitae produced in 1919, HW3/35; non-archival sources such as The Army List, The Indian Army List, Who’s Who, the Dictionary of National Biography, The Times and The London Gazette are not individually cited.

7. Hay Papers; Hay, Valiant for Truth, 71–89; Kirke papers, IWM82/28/1; Clauson papers, IWM80/47/2. Of particular value is an unsent letter of 8 October 1917 from Clauson in Mesopotamia to Crocker of M.I.1(b), hereafter ‘Clauson letter’ – this is reproduced in Ferris, British Army and Signals Intelligence, 209–13; Gill, War, Wireless and Wangles. Gill served in wireless intelligence in the War Office and then in Egypt, Cyprus, Salonika and the UK, he is a reliable source, albeit given to a relentless facetiousness; Tuohy, Crater of Mars. Tuohy served in the War Office and then as an Intelligence Corps officer on the Western Front, his writings on Comint are reliable on matters of which he had direct experience.

8. Johnson, Evolution of British Sigint, 7–19.

9. For the development of cables and their military and commercial significance see Kennedy, “Imperial Cable Communications”; Winkler, Nexus; and Ferris, “Before ‘Room 40’,” 435.

10. ‘Telegraphic Censorship during the South African War 1899–1902’, General Staff, 1903, WO33/280; Ferris, “Before ‘Room 40’,” 435.

11. An award worth approximately £9,700 in present day terms, https://www.measuringworth.com accessed 29 December 2015. Royal Engineers Institution, “Anderson memoir.” I am grateful to Jim Beach for this reference.

12. Ferris, “Before ‘Room 40’,” 437–41.

13. ‘Development of DMI’; see also Fergusson, British Military Intelligence, 219–25 for an account of the ‘special section’.

14. ‘Development of DMI’. ‘Special Duties’ was a euphemism for espionage and counter-espionage.

15. Organisational reform apart, a factor in the formal transfer of responsibility may have been the suspicion that Captain W.H. Cromie, War Office librarian until his removal from post ‘for irregular conduct’ in 1902, was spying for the French. For this and the wider development of the War Office library, see Beaver, “Intelligence Division Library.”

16. ‘Permanent Establishment of the Mobilisation and Intelligence Division: Report of Lord Hardwicke’s Committee’, War Office, March 1903, WO32/6922; ‘M.O.5(e) War Diary’; General Staff, ‘Staff Manual – War’, 1912, WO32/4731; General Staff, ‘A War Book for the War Office’, WO33/688.

17. 1907 course, WO279/515; 1908 course, WO279/19; Fergusson, British Military Intelligence, 220.

18. Wilson (DMO) to Haig (CGS, India) 19 August 1910, WO106/59; Royal Engineers Institution, “Anderson memoir”; General Staff, ‘Manual of Cryptography’, 1911, IWM ID 60471.

19. General Staff, Field Service Pocket Book 1914, 214–5; Muirhead, “Military Cryptography,” 1677–8; Ferris, “Before ‘Room 40’,” 444.

20. ‘Historical Sketch’; ‘History of M.I.1(b)’; Cartier, cited in de Lastours, guerre des codes secrets, 132; Kahn, Codebreakers, 299–304.

21. Two 1907 reports by the Simla bureau survive in the possession of GCHQ. Both deal with Russian ciphers and, although both contain the texts of deciphered messages, their avowed purpose is to explain the workings of the cipher in order that readers can decipher messages in these systems themselves. 40 copies of each report were printed. I am grateful to GCHQ’s Departmental Historian for sight of these items.

22. In 1913 Muirhead was seconded from his regiment to learn Russian, possibly as a prelude to a tour in the Simla bureau.

23. Cockerill, What Fools We Were, 19; Cockerill memoir, IWM86/2/1. Cockerill, with assistance from Church, was the author of the 1903 report on censorship in the Boer War (fn.10).

24. T1/11937/4860, 18311, 23402, 23991 and 25777 detail War Office negotiations with the Treasury over M.O.5(e) posts in 1914 and provide some details of the individuals involved; Crocker personal file WO339/12607; Rachel Strachey to Lady Strachey, 27 September 1914, IOR/Mss. Eur F127/338.

25. ‘Circular Memorandum No. 8’, Director of Signals, GHQ BEF, 19 August 1914, WO95/57; ‘Notes on the working of the system defined in the Staff Manual, War, so far as Section O.B., General Staff, is concerned’, GHQ BEF, 1 October 1914, WO95/1; ‘M.O.5(e) War Diary’.

26. Although by 1918 the Admiralty’s Comint section was officially designated ID25, the popular title of ‘Room 40’ is used throughout this article. For background see Beesly, Room 40; Gannon, Inside Room 40; Hiley, “Strategic Origins.”

27. ‘The following telegram, sent by the Belgian Headquarters, Antwerp, to the Minister of War at Paris has been intercepted …’, War Office to GHQ, M.O.5 No. 11, 25 August 1914, WO33/713.

28. Beesly, Room 40, 3.

29. ‘M.O.5(e) War Diary’. Nothing is known of the design of Pletts’ invention, although the fact that he, like Anderson, patented a form of slide rule may offer some clue.

30. Anderson’s visit was officially as Chairman of the Army Sanitary Committee, a role that reflected his background in military construction and civil engineering and which he combined with heading M.O.5(e).

31. ‘M.O.5(e) War Diary’; Kahn, Codebreakers, 304–5.

32. Kirke diaries; ‘M.O.5(e) War Diary’. Church was posted to GHQ BEF in December 1914, where he had some involvement in BEF ‘cipher work’ until Apr 17 when he became responsible for press visits, censorship, etc. (Kirke diaries; ‘Reorganisation of Intelligence branch GHQ’ WO158/961).

33. Hiley, “Strategic Origins,” 260–4; Kahn, Codebreakers, 299–304; ‘M.O.5(e) War Diary’.

34. Baker, Marconi Company, 21; Round personal file, WO339/30747. Round, a pre-war pioneer of DF for Marconi, subsequently became heavily involved in developing DF for the Admiralty (T 173/428).

35. Macdonogh to Edmonds, late 1922 or early 1923, CAB45/141.

36. ‘M.O.5(e) War Diary’; ‘History of M.I.1(b)’; Freeman, “M.I.1(b),” 210–11.

37. ‘Historical Sketch’; ‘Development of DMI’.

38. Simpson personal file, WO339/9788; ‘Improvement of Wireless Telegraphy communication between Great Britain and Russia: Report by Capt Adrian Simpson’, February 1915, WO106/1141.

39. Jeffrey, MI6, 99–102; Gill, War, Wireless and Wangles, 13–5. Gill was one of those allocated to ‘special wireless work’. The account given here is of necessity a simplification of a complex and often acrimonious episode involving the Secret Service, War Office and Foreign Office, best followed in the correspondence between Moscow and London in FO371/2449.

40. Gill, War, Wireless and Wangles, 15–6, 27 (Simpson appears as ‘Major Amplifier’); Nesbitt-Hawes memoir, Military Intelligence Museum, Chicksands, Acc. No. 198; ADM116/1454.

41. French to Hall, 18 December 15, HW7/24.

42. For context see Ferris, “Airbandit.” WTS reporting on air raids during 1916 and 1917, ADM137/4305 and 4355; on ‘giant aeroplane’ activity in 1918, AIR1/561. Three WTS reports on ‘Enemy Wireless Stations’ in 1918 survive, No. 58 of 15 April 1918 and No. 62 of 25 June 1918, NARA, RG120/105 Box 6699; No. 73 of 25 October 1918, ADM137/4684.

43. ‘Historical Sketch’; ‘Development of DMI’.

44. Hay, Valiant for Truth, 58–9; Fraser CV HW3/35; Tyndale personal file, WO339/18120. Tyndale, a master at Winchester School pre-war, had worked in M.O.5(e) during the summer of 1914 before enlisting. His uncle, a civil engineer in the War Office, and Anderson were acquaintances.

45. War Office to Treasury, 15 April 1916, T1/11937/10378; ‘Development of DMI’; ‘Lists’; Hay, Valiant for Truth, 60–1. 2 Whitehall Court is usually associated with ‘C’ (Captain Mansfield Cumming RN, head of the Secret Service) who used a top floor flat as his headquarters and housed parts of the Secret Service in others.

46. Childs, Before the Curtain Falls, 122. Childs uses transparent aliases for individuals, thus Day = Hay, Brooke = Brooke-Hunt, Herbert = Hitchings and MacDonald = MacGregor.

47. ‘History of M.I.1(b)’; ‘Lists’; M.I.1(b) tea fund for November and December 1917, HW3/185.

48. ‘History of M.I.1(b)’. This refers to military messages, Room 40 was responsible German naval and diplomatic wireless.

49. Kahn, Codebreakers, 310–11; Denniston to Crocker, 20 June, 25 August and 17 September 1917, HW3/184; Childs, p.123. ‘Für GOD’ solutions were also shared with the French.

50. ‘Historical Sketch’; ‘Development of DMI’; ‘Lists’; Kirke diaries, passim; Booker personal file, WO 339/23736.

51. HW 3/185; Kahn, Codebreakers, 372–3.

52. ‘History of M.I.1(b)’; ‘Historical Sketch’; ‘Development of DMI’; ‘Lists’; Hay to I(e)C, 22 August 1918, ADM134/4700. M.I.1(d)’s responsibility for the ‘distribution and safeguarding of military codes and ciphers’ had already been taken over in September 1918 by M.I.1(g), a new section formed to deal with aspects of deception and security in the field, paralleling developments in the management of deception and signals security in GHQ BEF (‘The Security Section’, GHQ(I), 23 October 1918, AIR1/1155; Memorandum by GS(I) 4 November 1918, WO158/961).

53. In the Admiralty cryptanalysis and cryptography were never combined, remaining the responsibility of the intelligence and signals divisions respectively. Hay, Valiant for Truth, 78–9; M.I.1(b) to Coutrney Forbes (Foreign Office), 15 March 1919, HW3/186.

54. Crocker to French, 15 April 1918, HW3/185; M.I.1(b) to R.H. Campbell, 25 April 1918, HW3/186 (Campbell was the conduit for M.I.1(b) diplomatic reporting to the Foreign Office); Kahn, Gentlemen’s Mail, 11–2; Barker, The History of Codes and Ciphers, 31.

55. Center for Cryptologic History, The Friedman Legacy, 101.

56. Denniston, “Between the Wars,” 57 (original in HW3/32). Written from memory in 1944, this is an important source for the history of British Comint before 1939 but Denniston’s statements are not always completely borne out by archival evidence.

57. War Office/Admiralty correspondence dealing with interception is in ADM 223/772.

58. See Freeman, “M.I.1(b),” 213–4; and Freeman, “Zimmermann,” 138–41.

59. At the time the French Ministry of Marine possessed no cryptanalytic bureau of its own and Cartier’s relationship with the British Admiralty was less cordial than that with the WO and BEF. Tuohy, employed in the War Office around this time to maintaining a map of German submarine dispositions from ‘wireless bearings and other information’, deprecated the fact that this duplicated the Admiralty’s more successful efforts. Kahn, Codebreakers, 277–8, 303. Tuohy, The Crater of Mars, 92; Kirke diary, 23 January and 15 June 1915; Decorations awarded to France, WO388/2.

60. AIR1/754; ‘Biography – Major H.P.T. Lefroy DSO MC RE’, AIR1/728; Tuohy, The Crater of Mars, 137–48; AIR1/996. The intelligence value of air-ground communications was not only the current activity of spotter aircraft but the resultant insight into the changing distribution of German artillery units.

61. The interception of ground returns was known in the BEF as ‘Intelligence Telephone’, usually abbreviated as ‘IT’ or ‘I Toc’. For a detailed description of I Toc operations see Beach, Schürrhoff Diary.

62. Kirke diaries, passim; Priestley, Signal Service, 105–11; Ferris, British Army, 25–52.

63. ‘History of M.I.1(b)’; Priestley, Signal Service, 165; 4th Army Telephone Directory, November 1917 and December 1918, WO95/494.

64. ‘History of M.I.1(b)’. The identification of potential cryptanalysts became more systematic as the war progressed, with the language skills of all potential intelligence officers being formally assessed and Hay introducing a test for potential cryptanalysts. See Hitchings personal file WO339/56781; Hay, Valiant for Truth, 62.

65. Mayo personal file, WO339/80855; CV in HW3/35.

66. Childs, Before the Curtain Falls, 119; MacGregor personal file, WO339/32075. The manual (‘Enemy Codes and Their Solution’, I(e)C, January 1918, ADM137/4660) dealt exclusively with codes. For ciphers readers were referred to the 1911 manual (fn.18).

67. British Mission in Washington to War Office, 3 May 1917, WO106/1512; Beach, “Special Intelligence Relationship,” passim; French (M.I.1) to Van Deman (War Department), 21 March 1918 cited in Barker, Codes and Ciphers, 23.

68. Hay, Valiant for Truth, 60; Childs, Before the Curtain Falls, 119, 122–4, 135–6; Barker, Codes and Ciphers, 17–9; Kahn, Gentlemen’s Mail, 45–6; correspondence between the AEF and British Comint authorities is in NARA Record Group 120 Boxes 5752, 5766 and 5767; Office of Chief Signal Officer, Code Compilation Section, passim.

69. Office of Chief Signal Officer, Radio Intelligence Section, 18. The others named were the Frenchmen Cartier and Painvin, and Hitchings and Wright of GHQ BEF.

70. For an examination of Comint’s contribution to all-source intelligence in the BEF see Beach, Haig’s Intelligence.

71. Leith-Ross papers, National Army Museum; R C Thompson papers, IWM PP/MCR/424 (these are largely uninformative on Comint); Pogson (HQ India) to Campbell Thompson, 21 June 1916, HW3/183; Clauson papers.

72. Sheffy, Palestine Campaign, 217–62; ‘Report on Turkish ciphers’, M.I.1, 28 Jul 1916, HW3/183. Clauson had spent April to July 1915 attached to M.O.6 and served on general intelligence duties in Egypt until joining M.I.1(b) in May 1916 (Clauson papers).

73. GHQ Egypt to DMI, 25 Mar 1916, WO157/702; Gill, War, Wireless and Wangles, 27–34 (Lefroy appears as ‘Major Triode’).

74. ‘History of M.I.1(b)’; Gill, War, Wireless and Wangles, 67–70 (Strachey appears as ‘Mr. Inductance’).

75. Lycett to Tozer, 2 May 1948, HW3/88.

76. ‘History of M.I.1(b)’; Kitchener to Monro, 14 December 1915, WO95/4756; Hay, Valiant for Truth, 77; War Office to Salonika, 22 January 1917, WO95/4757. Cartier, cited in Lastours, guerre des codes secrets, 138, states the French also read this traffic.

77. ‘History of M.I.1(b)’; Kirke diaries, passim; Hay, Valiant for Truth, 60; WO157/753; Robertson to Lloyd George, 9 January 1917, WO106/1511.

78. Ferris, British Army, 334–5.

79. ‘Clauson letter’. The 1st Australian Wireless Signal Squadron operated two receivers for ‘Special Army Work’ at GHQ Mesopotamia from May 1917 until April 1918, Australian War Memorial AWM4 22/16.

80. One of Lefroy’s first actions in Mesopotamia was to rename the Special Wireless Section as the ‘Wireless Press Section’, the cover term used in Egypt; in February 1918 it became No.4 GHQ WOG, War Diary, WO95/5001; ‘History of M.I.1(b)’; telegrams between DMI and GHQ Mesopotamia, October and November 1917, Clauson papers (selection in Ferris, British Army, 213–6); WO95/4387.

81. ‘Clauson letter’; Sheffy, Palestine Campaign, passim; I(e) Salonika reports, January and February 1917, WO157/753; diagrams of enemy wireless networks in War Diary of Director of Army Signals, Salonika, WO95/4783.

82. For context see Marshall, “Russian Military Intelligence”; Neilson, “Joy Rides?”; ‘History of the British Intelligence Organisation in Russia’, M.I.1(a), 26 February 1917, WO106/6190. The Admiralty’s close relationship with their Russian counterparts is well known, see Beesly, Room 40, 181–2.

83. ‘A former Soviet Communications Service chief’ cited in Hammant, “Russian and Soviet Cryptology,” 239; distribution of M.I.1(b)’s July 1916 report on Turkish ciphers (fn.75); DMI report, 4 January 1917, forwarding Comint on Turkish military intentions, WO106/1511; DMI to C-in-C India, 3 July 1916, IOR/L/MIL/17/5/3256, forwarding Russian intelligence, almost certainly Comint; Marsh to War Office, 7 March 1916, forwarding translations of messages and cipher system, ADM223/787.

84. ‘Clauson letter’.

85. In the case of Clauson and Crocker of M.I.1(b) a close personal friendship did exist, as evidenced by the tone and subject of parts of the ‘Clauson letter’.

86. Lycett to Tozer, 2 May 1948, HW3/88.

87. ‘History of M.I.1(b)’; Ferris, British Army, 299.

88. One exception, currently obscure but worthy of further research, is work against Russian targets following the October Revolution.

89. ‘The Service of Intelligence to the British Forces in Italy’, 20 May 1919, WO106/1550; ‘History of M.I.1(b)’; WO106/1550; WTS dealing with ‘Enemy Wireless Stations’, 1918 (fn.42).

90. ‘M.O.5(e) War Diary’; Tighe to War Office, 17 May 1915, WO 33/858.

91. Distribution of Int E P/58a of 21 February 1918, NARA RG 457/190 Box 124 and handwritten draft of I(e) BEF report, n.d. but from internal evidence probably late August 1918, ADM 137/4398.

92. ‘History of M.I.1(b)’; WO339 and 374.

93. ‘Historical Sketch’; ‘Development of DMI’; ‘Lists’; Marshall-Cornwall, Rumours of Wars, 40; Hay, Valiant for Truth, 79–81, 84.

94. Hall to Thwaites, 26 November 1918, WO32/21380.

95. Curzon to Long (First Lord), 24 March 1919, ADM1/8637/55.

96. Hall to Thwaites, 26 November 1918; Thwaites to Hall, 28 November 1918, WO32/21380.

97. Long to Drogheda (Foreign Office), 28 March 1919, HW3/34; Sinclair to Long, 28 March 1919; Long to Curzon, 29 March 1919, ADM1/8637/55.

98. Cork Street Book.

99. Internal Admiralty minute to DNI, probably by Denniston, undated but c. August 1919, HW 3/35; ‘Development of DMI’; ‘Lists’. Although the army quickly disbanded its organisation in UK and France, army Comint in the Middle East continued without a discernible pause.

100. War Office to Treasury, 13 October and 20 December 1919, T1/12462; Historical Notes, DD(C) [Denniston], HW3/33; report on ‘India as regards Cryptographical and Wireless Intelligence requirements’, Maj E.E. Calthrop, March 1921, WO208/5062; ‘Development of DMI’; ‘Lists’.

101. For Tiltman’s life see Erskine and Freeman “Brigadier John Tiltman.”

102. ‘Development of DMI’.

103. 50 per cent of GC&CS’s cryptanalytic staff were ex-M.I.1(b). The ‘Room 40 tradition’ and its implications for the historiography of British Comint is examined in Ferris, “Road to Bletchley Park.”

104. ‘A History of British Sigint 1914–1945, Vol 1’ p.7, HW43/1. For the Admiralty as a central command centre, a development made possible by advances in communications, see Lambert, “Strategic Command and Control.”

105. ‘Miscellaneous Correspondence to Col. Tozer, 1948–49’, HW3/88. There appears to have been no effort to consult those former members of M.I.1(b) still serving in GC&CS.

106. E.g., Lieutenant Colonel Frederick Nicholls who served in collection posts in France, Russia, Iraq, Afghanistan, Persia, Palestine, India and Burma (HS9/1099/1).

107. What follows is based on the author’s collation of the biographical details of pre-1939 British Comint personnel – this is a work in progress and the conclusions are tentative, but it is hoped to eventually produce a more refined prosopography.

108. Beesley, Room 40, 303; W.F. Clarke memoir, HW 3/6.

109. Hay, Valiant for Truth, 60; for the army’s increasingly methodical selection and management of intelligence personnel see Beach, “Intelligent Civilians in Uniform.”