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  • Writer's pictureHelen Fry

The Spy who Saved MI6

Updated: Apr 11, 2023

For nearly 30 years Thomas Joseph Kendrick was the most senior spymaster in Europe for SIS – the British Secret Intelligence Service (otherwise known as MI6). During the instability and turmoil of Europe after WWI, SIS posted Kendrick to Vienna as the British Passport Control officer – a cover for his real work as head of the SIS station there. During the 1920s and 1930s Vienna was the hub of espionage. For thirteen years Kendrick recruited and ran agents and informers for MI6, operating extensive spy networks into Hungary, Czechoslovakia, Romania, Italy and Germany. He gathered precious information for Britain about the threat faced in the Soviets, and later in the 1930s the still greater threat in the Nazis.

Hitler turned his attention to Austria and Czechoslovakia and Kendrick’s work for SIS assumed even greater significance. The period between March and August 1938 was chaotic as Kendrick’s intelligence work came under strain. He embarked on a humanitarian mission to save Austria’s Jews from deportation to concentration camps and facilitate their exit from Austria to Britain, Palestine and British Dominions. With increasing pressure from London to limit immigration to the UK, Kendrick started to issue fake visas and documents to Jews. His rescue efforts included the saving of many of the Viennese intelligentsia: prominent doctors, surgeons, musicians, artists, psychoanalysts, architects and businessmen. He is credited officially with saving up to 200 Austrian Jews a day after Hitler annexed Austria in March 1938. He went beyond the call of duty and disobeyed official government visa regulations to rescue over 10,000 Austria Jews. Some later worked for him in WWII as ‘secret listeners’.

As WW2 loomed in the autumn of 1938, Kendrick was tasked with setting up one of the longest and most far-reaching intelligence operations that sprang into action at the start of the war in September 1939. With no blue-print, he masterminded an operation to eavesdrop on the conversations of over 10,000 German prisoners of war at his three special sites, including Hitler’s generals and Field Marshals at Trent Park in North London, after their capture on the battlefields. The intelligence gained by Kendrick’s clandestine unit – including the work of the ‘secret listeners’ – has now been recognised by Historic England as being “on a par with the code-breaking at Bletchley Park for the outcome of the war.

Although the bugging operation began in the Tower of London, it swiftly moved to Trent Park. In October 1939, Trent Park was requisitioned by Kendrick and its rooms ‘wired for sound’ – with bugging devices placed in the light fittings, fireplaces, billiards table and even the trees in the grounds. It opened in January 1940 until November 1945. Results were swift. Already in spring 1940 his team of secret listeners overheard references to X-Gerat, a new kind of navigational beam system on German aircraft for bombing targets, and a wealth of information on the U-boat campaign, development of new technology and weapons for the German navy, its aircraft and tanks, and some of the earliest references to atrocities, including the mass killing of Jews.

From May 1942 Trent Park was reserved for high-ranking German officers and Generals. Coming fresh from the battlefields, they were duped into believing they were being held there as befitted their military status. the Generals quickly became off guard and Kendrick’s intelligence officers created conditions that enabled them to totally relax and become unguarded in their conversations – in essence, the place was run like a ‘gentleman’s club’. The Generals devoted time to learning languages, the arts, music and other subjects, painting and drawing, or playing cards, table-tennis and billiards. Little did they suspect that everywhere was bugged.

These reveal how quickly the Generals aligned themselves into two political divisions: pro-Nazis and anti-Nazi. While they wrangled over politics and loyalty to the Third Reich, they began to inadvertently reveal some of Hitler’s closely protected military secrets; the most precious of which related to the deadly ‘secret weapon’ programme: the V1 (doodlebug), V2 and later V3, as well as the development of the atomic bomb.

The discovery of the ‘secret weapon’ development site at Peenemünde in a conversation between two Generals in March 1943, led to Churchill directly ordering the famous bombing of Peenemünde in Operation Crossbow a few months later in August 1943. It is believed that the discovery of the V1 and V2 from the German Generals, alongside the cracking of the Enigma at Bletchley, changed the course of the war, shortened the war and saved hundreds of thousands of lives. Lieut. Colonel St. Clare Grondona (Kendrick’s deputy) later succinctly summarised the importance of their work when he wrote: ‘Had it not been for the information obtained at the centre, it could have been London and not Hiroshima which was devastated by the first atomic bomb.’ Like Bletchley Park, the fact that Kendrick’s unit’s existence remained unknown for over six decades, and is still largely unknown today, was a testament to its success.

Kendrick's achievements went beyond being at the centre of war-winning against Nazi Germany. His secret unit began to gather intelligence for the British on Russia. Although Russia was an ally for much of the war, by 1943 it had emerged again as the long-term threat. Kendrick's life cam full circle as he found himself spying again on the duel threat of Russia and Nazi Germany.

Behind Kendrick’s incredible wartime work, lies another equally important legacy. My new book Spymaster: The Man who Saved MI6 has enabled the first far-reaching assessment of Kendrick as one of the greatest spymasters of the twentieth century; a man with a moral compass as a Righteous Gentile; and in the end the spy who saved MI6 at a time of supreme crisis in the service.

Catch my podcast interview with Al Murray and James Holland:-


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