Churchill’s Golden Geese: The Role of Ultra in Allied Strategy and Operations

Denis Smyth

Department of History, University of Toronto, Canada

In November 1924 Britain’s Chancellor of the Exchequer, Winston Churchill, complained about being denied access to secret messages sent by the Soviet government, which had been intercepted and decoded by British experts:

All the years I have been in office … I have read every one of these flimsies (i.e., decrypts) and I attach more importance to them as a means of forming a true judgment of public policy…than to any other source of knowledge at the disposal of the state. (Andrew 1985, 315–316)

Although Churchill’s protest fell on deaf ears at that time, he was in a more authoritative position, as Prime Minister, to call for unfettered access to the signals intelligence (SIGINT) generated by Britain’s codebreakers in 1940. Even more convinced of the need to exploit the unique revelations about Nazi Germany’s plans and priorities provided by the cryptanalysts of Britain’s Government Code and Cypher School (located at Bletchley Park in Buckinghamshire) as his country fought for its very survival, he insisted on seeing “authentic documents” in “their original form” – not summaries and assessments of the enemy’s encrypted radio messages which had been “sifted and digested by the various Intelligence authorities” (Hinsley et al. 1979, 295). In the following month, September 1940, Churchill actually expanded his demand, to review the raw text of enemy signals, to a directive that he be sent, every day, all the decoded intercepts of messages encrypted on the Enigma machine, which was used by all branches of the German armed forces to mask their radio communications (295). The Prime Minister’s request to read, in person, each and every Enigma decrypt was not overly ambitious at the time he made it, since Bletchley Park (GC&CS) was only successfully attacking a single enemy key then – the general-purpose one of the German Air Force, which was designated as Luftwaffe “red”, and yielded about fifty decrypts a day (Hinsley 1993, 411). However, that number would increase exponentially, as British cryptanalysts united mathematical genius with imaginative insights (such as divining the errors made by Enigma operators which undermined the device’s notional impregnability) to solve the Germans’ ciphers. So, in spite of the seemingly astronomical odds against deciphering even an individual letter in an Enigma-encrypted message – something like a hundred and fifty trillion to one – British codebreakers managed to beat them. By mid-1942, thanks to the sophisticated techniques and technology employed at GC&CS, three to four thousand radio messages transmitted by all the Nazis’ armed forces, including the Abwehr (the Secret Intelligence Service of the German Supreme Command), were being read daily (Hinsley 1993, 422; Smyth 2010, 11–13).

            Indeed, so rich was the intelligence harvest reaped by the boffins of Bletchley Park that it soon exceeded the capacity of any individual mind – even the tireless intellect of Britain’s Second World Wartime leader – to master in full. Accordingly, Churchill resigned himself, from the summer of 1941, to receiving only a daily selection of the most important decrypts, along with summaries of others (Hinsley 1979, 295–296). Yet this restricted secret intelligence diet was still sufficient to enable the Prime Minister to quiz his generals on how they intended to counter enemy plans and preparations revealed by “Ultra” (British code-name for the intelligence produced by the reading of high-level enemy ciphers). This was a lesson that General Sir Claude Auchinleck learned to his cost in early August 1942, when Rommel’s Panzerarmee Afrika stood only sixty miles from Alexandria, and Churchill visited the Egyptian front, in person, to see what could be done to prevent the Suez Canal and Middle-Eastern oilfields falling to the Nazis. To the Prime Minister the British strategic plight, at this stage of the Desert War, seemed almost inexplicable, given the intelligence advantage their Eighth Army now enjoyed over the Italo-German forces, with access – courtesy of GC&CS – “to every enemy cipher in use in the African fighting” (D’Este 2008, 580–583; Hinsley 1993, 4–5). Yet Auchinleck – who was both British Commander-in-Chief Middle East and in charge of the Eighth Army – failed to offer any remedy for this military malaise when subjected to an intelligence-based interrogation by Churchill, which was recorded by an eavesdropper:

Winston gave this astonishing description of what Rommel was doing and said to the Auk: “Well, what are you going to do about that? What’s your plan?” I mean he was incredibly well-briefed, of course he’d got his Ultra, he’d sort of thought it out: Rommel’s doing this, what are we going to do? (Hamilton 1982, 569–573)

Churchill promptly appointed a new commander of the Eighth Army, General Bernard Law Montgomery, who used Ultra to considerable operational effect in beating back the Axis threat to the Nile Delta once and for all during the period late August to early November 1942 – even if he failed to deliver on his promise to “hit Rommel for six out of Africa” by the end of the year (Bennett 1989, 139-81).

            However, it must also be admitted that not all of Churchill’s Ultra-inspired interventions in the conduct of the Desert War had such happy outcomes. Thus, in mid-May and, again, in mid-June 1941, the Prime Minister had egged on Auchinleck’s predecessor, General Wavell, to launch abortive assaults against Rommel’s Afrika Korps, upon the basis of the very limited Enigma traffic being read by Bletchley Park about that enemy force, at that time. This essentially “random selection of secrets” had divulged nothing about the superiority of the Germans’ tanks and anti-tank weapons, especially the lethal 88mm gun, only a dozen of which sufficed to repel the Eighth Army’s June attack (Bennett 1989, 36–45). Still, by the time of these setbacks in the Western Desert, the British Chiefs of Staff (COS) had acted to improve the apparatus of central intelligence evaluation, not least to equip them to cope with Churchill’s Ultra-informed interventions in the conduct of military operations and the formulation of strategic policy. Accordingly, in May 1941, they finally provided the Joint Intelligence Committee (the JIC: the War Cabinet sub-committee which was meant to keep the Chiefs fully briefed on clandestine matters) with enough experts to assess the growing flow of data from all sources being gathered by Britain’s information warriors. Consequently, the COS could now integrate objective appreciations of enemy intentions and capabilities into their own military moves and strategic schemes. This crucial administrative reform was followed, in July of the same year, with another significant measure: the Intelligence branches of the British Army, the Royal Navy and the Royal Air Force were directed to supply the COS with summaries of the latest Ultra – usually several times a day. Now that Churchill had to share access to this “special intelligence” (another cover name for the SIGINT) with Britain’s other warlords, he could no longer rely on it to overbear the Chiefs’ resistance to his micromanagement of military affairs. Henceforward, the COS felt they knew enough about their Nazi foe to take or leave prime ministerial demands, prompted by his receipt of some Ultra material, for particular actions or reactions. By the turn of 1942–43, indeed, Churchill’s attempts to affect the conduct of military operations, in the light of some item of “special intelligence,” had all but come to an end. At that stage of the war, the huge numbers of decrypts, the proficiency of the streamlined British system for evaluating and exploiting them, and the establishment of an Anglo-American command structure impervious to Churchill’s exhortations, together put paid to his Ultra-prompted interventionism (Hinsley 1993, 411–412, 422–425).

            Yet, it would be wrong to underestimate Churchill’s role in ensuring that the “Ultra secret” played a vital part in the Anglo-American war effort against Nazi Germany. Thus, in October 1941, when four of Bletchley Park’s most gifted codebreakers – including the brilliant mathematician, Alan Turing – directly appealed to the Prime Minister for the additional support staff they needed to continue breaking Enigma – he immediately issued the following directive to his senior staff officer, General Hastings “Pug” Ismay: “Make sure they have all they want on extreme priority and report to me that this has been done” (Erskine and Smith 2011, x–xiii). Churchill’s executive intervention broke the bureaucratic logjam: Bletchley Park’s staff complement grew from 1,576 in March 1942 to 8,743 (two-thirds of whom were women) by December 1944 (Grey and Sturdy 2008, 320–321; Aldrich 2010, 26–27).

            This investment of human capital in GC&CS’s cryptanalytical campaign against the fascist powers yielded the most handsome of strategic dividends. Not only did the armies of the Western Democracies that ventured forth to do battle with the legions of Hitler’s Germany and Mussolini’s Italy have greater knowledge about their enemies than any previous fighting formations in history, but they were also able to use that secret information to decisive effect. In fact, this ability to read the radio communications of the German High Command enabled their Allied counterparts to practice strategic deception successfully. By laying bare Hitler’s strategic anxieties Bletchley Park’s boffins gave British deception planners the opportunity to attune their ruses de guerre to the Führer’s fears. Thus, the deceptioneers played upon Hitler’s conviction that an Anglo-American invasion of Greece was probable in the summer of 1943, in order to divert German troop deployments from the Allies’ real target, the island of Sicily (Smyth 2010, 47–49, 70–71, 272–277). Even more crucially, the deception planners also managed to retard the Germans’ reinforcement of their units contesting the Allied invasion of Normandy, after 6 June 1944, by pandering to Hitler’s idée fixe – duly disclosed by Ultra – that the latter landing was but a feint to distract his attention from the main amphibious assault, to follow subsequently against the Pas-de-Calais (Howard 1990, 105, 110–111, 185–193; Holt 2004, 565–567, 571–575, 579–584).

            As the consumer-in-chief of Ultra, and as catalyst for the creation of the set-up that eventually integrated it into strategic decision-making and deception-planning, Churchill played the leading part in the practical exploitation of this unprecedentedly rich intelligence source. He remained mindful, after the fighting was over, of the immense contribution the codebreakers had made to victory, as much in guarding their vital secrets from prying eyes as in passing them on to him. Accordingly, he referred to Bletchley Park’s finest as “the geese that laid the golden eggs and never cackled” (Smith 2011, 137). Remarkably now, however, this most secret of Second-World-Wartime intelligence sources – the very texts of the decrypted enemy messages delivered into Winston Churchill’s own hands – is now made available for research and consultation, in the HW 1 series, which forms part of this online resource.


Aldrich, Richard J. 2010. GCHQ: The Uncensored Story of Britain’s Most Secret Intelligence Agency. London: Harper Press.

Andrew, Christopher. 1985. Secret Service: The Making of the British Intelligence Community. London: Heinemann.

Bennett, Ralph. 1989. Ultra and Mediterranean Strategy. New York: William Morrow.

D’Este, Carlo. 2008. Warlord: A Life of Winston Churchill at War, 1874–1945. New York: Harper.

Erskine, Ralph, and Michael Smith, eds 2011. The Bletchley Park Codebreakers: How Ultra Shortened the War and Led to the Birth of the Computer. 2nd ed. London: Biteback Publishing.

Grey, Christopher, and Andrew Sturdy. 2008. “The 1942 Reorganization of the Government Code and Cypher School.” Cryptologia 32 (4): 320–321.

Hamilton, Nigel. 1982. Monty: the Making of a General, 1887–1942. 2nd ed. Toronto: Fleet Books.

Hinsley, F. H. 1993. “Churchill and the Use of Special Intelligence.” In Churchill, edited by Robert Blake and Wm. Roger Louis: 407–426. New York: W.W. Norton.

Hinsley, F.H. 1993. “Introduction: The Influence of Ultra in the Second World War.” In Codebreakers: The Inside Story of Bletchley Park, edited by F. H. Hinsley and Alan Stripp:1–13. Oxford: Oxford University Press.

Hinsley, F. H., E. E. Thomas., C. F. G.  Ransom, and R. C. Knight. 1979. British Intelligence in the Second World War: Its Influence on Strategy Operations, vol. 1. London: HMSO.

Holt, Thaddeus. 2004. The Deceivers: Allied Military Deception in the Second World War. New York: Scribner.

Howard, Michael. 1990. British Intelligence in the Second World War, vol. 5, Strategic Deception. London: HMSO.

Smith, Michael. 2011. The Secrets of Station X: How the Bletchley Park Codebreakers Helped Win the War. London: Biteback Publishing.

Smyth, Denis. 2010. Deathly Deception: The Real Story of Operation Mincemeat. Oxford: Oxford University Press.

Cookies Notification

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Find out more.