Liddell Hart’s D-Day Prediction

By Andrew Stewart, trustee of the Liddell Hart Centre for Military Archives.

In 2006 the release of two files by the National Archives at Kew resulted in media interest in the revelations they contained about Basil Liddell Hart’s wartime activities. Both ‘The Times’ and ‘The Financial Times’ detailed investigations by the British Security Services into his possible involvement in a leak about the location for the invasion of Europe, known more popularly ever since as D-Day. Making sure this was not known was second only to ensuring the secrecy of Ultra – the successful decryption of German communications and the information this provided – and up until summer 1943 only the immediate Allied planning team knew. Twelve months later, for the vast majority of those who landed in northern France on 6 June, the first they learned of their destination was in the hours before. However, it was believed that Basil Liddell Hart, who was not in the small circle of military personnel in-the-know, had been told in advance details about the air and sea invasion.

Basil Liddell Hart in his study at Tilford House, Farnham, 1946. Liddell Hart 13/104/6.

A document written by Liddell Hart was the reason for MI5’s interest. Titled ‘Some Reflections on the Problem of Invading the Continent’, it was sent initially as a letter to Lord Beaverbrook and, in analysing potential military options, it had suggested the advantages of an indirect approach, such as a landing on the western coast of France between the Loire and the Gironde. The concern was the references it made also to Normandy, the actual target, and the deduction that the emphasis attached to air cover by General Sir Bernard Montgomery, the deputy commander of the invasion force, pointed towards “a more or less direct cross-Channel route”. Unbeknown to him, he had been monitored from well before the war’s start with reports collected from sources which ranged from describing him as “somewhat defeatist” through to his being pro-Nazi. When his note, now typed up as a memorandum, was shared with Duncan Sandys it quickly reached the Prime Minister and Chiefs of Staff. Sandys also submitted a written statement which stated Liddell Hart had mentioned in conversation the coast of Normandy and possibly the importance of Caen, which was indeed critical to the plan. All of this was seized upon as evidence that there was a failure of security and the military correspondent, whose loyalties were already considered questionable, was centrally involved.

Liddell Hart’s notes on invading the Continent. Liddell Hart 11/1944/5.

The media scrutiny of nearly twenty years ago provides most of the details of the resulting investigation but was far from complete. Much of the material gathered by MI5 was apparently destroyed although another folder includes exchanges between Churchill and General Eisenhower in which the American was warned about “the black sheep” military analyst (there was some suspicion that the leak might have come from one of his officers). The potential for some form of possible criminal action was considered at length but Liddell Hart remained completely ignorant of how close his reputation came to being destroyed. When interviewed by Brigadier Ian Jacob he denied his military contacts had told him anything and argued “his knowledge of it was arrived at by inferences drawn from his own observations”. He also proposed that he could see nothing wrong with having been told the plan as he was a “military expert”.

Closer investigation of his own papers within the archive, specifically the diaries and notes for 1943 and 1944, provides some evidence as to what actually might have happened. Whilst nobody was identified as the potential source, General Sir Frederick Pile’s name was the only one referenced directly by the MI5 investigators. According to his autobiography ‘Ack-Ack’, ‘Tim’ Pile had known Liddell Hart since the inter-war years and over the subsequent years they shared many discussions on military matters. In 1943 they met on five occasions and between January and March 1944 another three times. Most tellingly, Pile arrived for tea with Liddell Hart at High Wray House on Thursday 20 January before driving on to Edinburgh the following morning. Pile also indicated in his own published account that January had been when details about the invasion started to become more widely known amongst the senior military commanders who were involved. The problem is that in the several pages of Liddell Hart’s own hand-written notes of the meeting, there is no specific reference to Normandy. At the end of November, however, the two had met for lunch during which the discussion turned to a study made by Bernard Paget, then still commanding 21st Army Group but soon to be replaced by Montgomery. The two men discussed the investigation made of the Brittany coastal area and while it was agreed there were some good beaches, Liddell Hart noted that “the going would be easier if the advance swung eastwards through Normandy”. Other than in the 25 January note, this is the only reference that can be found, in the context of discussions of the invasion, to what proved to be the actual location. In a ‘Note for History’ written just after Christmas 1943 there were three mentions of ‘Overlord’, the invasion codename, albeit with little real detail beyond Plymouth as the location for an American Army Corps headquarters. The document did also reference ‘Anvil’, another key codename for the projected invasion, and whilst there may have been some details provided, it was a far from complete picture.

An extract from Liddell Hart’s papers describing his meeting where he was questioned on his knowledge of the invasion. Liddell Hart 11/1944/17.

There were also other military and political figures Liddell Hart met between June 1943 and January 1944 who could have unwittingly given him and his ever-active notebook inadvertent steers. Major-General Percy Hobart was another old friend and he stayed the night of 9 December. The resulting five-page ‘Notes for History’ of their discussions contained much privileged detail which would have been restricted information but, although massively indiscreet and perhaps indicative of the conversations between the two men, there was again no specific reference to Normandy. Another with whom he met was General Sir John Crocker who on D-Day commanded the British forces in I Corps which landed from the sea on Sword and Juno beaches and from the air to the east of the Orne estuary. From a very early stage he would have been fully aware of the plan and the locations involved. Nothing in the notes provided suggests anything more than general discussion about how the invasion would occur.

An extract from Liddell Hart’s diary showing Pile’s visit in January 1944. Liddell Hart 11/1944/1.

Clearly Liddell Hart had a wide and well cultivated network which provided valuable details about the Allied planning. Following his March meetings which he failed to realise had been convened to determine if he was guilty of treason or not, he promised to “become like an oyster” on the subject and not to write anything in his Daily Mail newspaper column. Not knowing the success of Allied operations orchestrated in large part by Ultra and its phantom agents, the secrecy of which remained intact beyond his death, he was unaware that the Germans were deceived into reaching an entirely different conclusion about Allied plans. Guesswork or treachery, Liddell Hart’s prediction fortunately remained confined to his own personal files and those of MI5.

A visiting professor in the School of Security Studies and a trustee of the Liddell Hart Centre for Military Archives, Andrew Stewart is Director of Conflict Research in the Centre for Historical Analysis and Conflict Research, the British Army’s think-tank.


In 1962, the War Studies Department of King’s College London was founded by Sir Michael Howard, lecturer in Military Studies and one of England’s foremost military historians. Two years later, Howard established a Centre for Military Archives at King’s to complement the new department. The Centre’s remit was simple: it would collect the papers of senior defence personnel of the twentieth century. The official launch of this archive was timed for 1964, to commemorate the 50th anniversary of the outbreak of the First World War. In 1973, the archive was renamed the Liddell Hart Centre for Military Archives in honour of Sir Basil Liddell Hart, whose own extraordinary collection of over 1000 boxes of papers is still the single largest, and one of the most often used, in the LHCMA.

2024 thus marks the LHCMA’s 60th anniversary. In those intervening years we have gathered the personal papers of over 800 senior defence personnel, and we thought this birthday year was a great opportunity to showcase just some of the items from the collection. Every month this year we will be publishing a blog post spotlighting one item or collection chosen by a member of staff. We hope you enjoy celebrating with us!

You can read last month’s post about the use of gas on the Western Front by clicking here.

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