8

SECRETS OF THE TOWER

In mid-September 1938, Kendrick arrived at MI6 headquarters at 54 Broadway Buildings to hectic scenes, as MI6 prepared for war.1 Hugh ‘Quex’ Sinclair, ‘C’, assured him, ‘I have your future under consideration.’² Sinclair was convinced that war with Nazi Germany was inevitable: it was just a question of when.³ He asked Kendrick if he would train operatives and agents for SIS to send on missions abroad. This is as much as is currently known about Kendrick’s work in this respect, because no files have been released that contain the names of the agents or their missions. That same month, Prime Minister Neville Chamberlain signed the Munich Agreement, in an attempt to avert imminent war with Adolf Hitler, who continued to threaten to annex the Sudetenland and Czechoslovakia. In later years, Chamberlain was to come in for fierce criticism over his appeasement policy; but a very different picture is now emerging about why he signed it. Britain was wholly unprepared for another war, just 21 years after the Great War. In a rare move, Sinclair intervened in government policy, telling Chamberlain that unless he signed the Munich Agreement, Britain would be at war with Germany immediately – at a time when Britain was ill-prepared both militarily and in terms of British intelligence structures.⁴ He advised Chamberlain to accept Hitler’s demands over Czechoslovakia and the Sudetenland.

Although the Munich Agreement did not avert a war, it did buy enough time for MI5 and MI6 to set up key intelligence units to fight the war when it came. It has been said that the intervention of the head of MI6 at this time demonstrated that Sinclair had emerged as ‘a policy advisor as well as intelligence supplier and analyst’.5 At no point did Sinclair or his successor, Stewart Menzies, even contemplate the notion that Britain would lose the war. Sinclair believed that a war was won on the basis of early and good intelligence, and therefore he planned a sweeping strategy that would leave no stone unturned. The plans included the establishment of a new section of SIS, known as Section D, to disseminate propaganda and conduct acts of sabotage.⁶ In 1938, Sinclair had also purchased the estate of Bletchley Park, in Buckinghamshire. During the war, it was there that the codebreakers cracked the German Enigma codes and intercepted enemy communications and signals.⁷ The history of Bletchley Park is well documented.

British intelligence believed that one of the most important sources of intelligence in any war was prisoners of war. Major General Sir William Thwaites once said in a training lecture: ‘The information of greatest value to the intelligence section of General Staff is that derived from the interrogation of prisoners and deserters, and the documents found on them.’⁸ Kendrick knew that to be true from his experience in the First World War. As another war loomed in the late 1930s, Sinclair had Kendrick in mind to establish a new unit that would spring into action as soon as war broke out. It would involve, for the first time, the mass recording of the unguarded conversations of German prisoners of war at secret locations under Kendrick’s command. In early 1939, alongside his training of SIS agents for the field, it was Kendrick’s task to find a suitable location for a wartime bugging unit. He earmarked rooms in the Tower of London for a hush-hush unit initially known as the Prisoners of War Collecting Centre, within fell under the auspices of MI1(h).⁹

Sinclair’s judgement that Kendrick was the right man to establish this new far-reaching intelligence-gathering unit was, in the end, proved correct. Kendrick could draw on his experiences in dealing with German prisoners in the Boer War and the First World War, and he was a past master at running a complex bureaucratic system and networks. But there was another reason for choosing him: from the outset, this would be a tri-service unit, featuring army, navy and air intelligence – the first such inter-services unit in the history of British intelligence. The smooth working of such a combined centre depended entirely on the breadth of mind and cooperation of the chiefs of the three service departments. This could not be taken for granted, as the services were used to working autonomously and had a history of rivalry and jealousies. Sinclair judged that Kendrick’s strength of character and his skill in managing interpersonal relationships and fostering cooperation meant that he could navigate the egos and agendas of individuals within the services. The success of the unit was to lay the foundations for intelligence work and tri-service cooperation right up to the present day.

The idea of listening into enemy conversations in war was not new. There is a fleeting reference in a military lecture to the tapping of enemy telephone lines in the field during the First World War – a development described as ‘pioneering’; but there are no further details in military sources.10 It is not known whether Kendrick had been involved in this, but it seems highly probable. The extent of what was unleashed by Kendrick’s skills can be gauged from the over 75,000 declassified transcripts and intelligence reports in the National Archives at Kew, London.¹¹ These provide a unique record of the unguarded conversations of over 10,000 German prisoners of war. The files, which were only declassified in the 1990s and have remained largely untapped by historians, reveal an extraordinary volume of intelligence and are relevant to every campaign of the war.

Prisoners of War Collecting Centre

On 1 September 1939, the day Hitler invaded Poland, Major Kendrick (as he now was) opened the Prisoners of War Collecting Centre in a special area of the Tower of London.¹² He had already arranged for a team from the Post Office Research Station at Dollis Hill, north London, to enter the site in late August in order to install microphones in the light fittings and fireplaces of the rooms.¹³ This had not been an easy task in the thousand-year-old fortress. Kendrick wrote that the team at Dollis Hill ‘helped us over a difficult stile at the outset at the Tower where conditions were about as unfavourable as can be imagined’, while the surveyor undertook ‘difficult work, demanding fine craftsmanship without which it would have been difficult to obtain the very satisfactory results’.14 The existence of this clandestine operation had to be closely guarded: if it became public knowledge, or if the German prisoners suspected anything, that would jeopardize one of the most important sources of intelligence collecting in the war. To protect the top-secret nature of this unit, Kendrick was given the freedom to choose his own staff. He selected his closest, most-trusted colleagues from his pre-war life to become part of a team that initially comprised no more than eight officers.¹⁵ They included Samuel Denys Felkin, who soon headed up the air intelligence section of the unit; Arthur Rawlinson (an interrogator from the First World War); and Edmund Pollak, the British businessman whom Kendrick had smuggled out of Vienna in March 1938.¹⁶

The centre could hold up to 120 prisoners at any one time. The first German POWs arrived in the latter half of September: 43 U-boat officers and other ranks from U39, the first enemy U-boat to be sunk in the war (off the coast of north-west Ireland, on 14 September).¹⁷ On 20 September, a further 38 German POWs were brought to the compound. All had to be interrogated and processed for intelligence. At this stage in the war (and even later on), prisoners were reluctant to divulge any information in interrogation, believing that Germany would emerge victorious. Kendrick’s staff kept strictly to the rules of the Geneva Convention, permitting no violence or unorthodox methods of interrogation: prisoners were only required to give their name, rank and number, as per the Geneva Convention. Kendrick had a clever ruse to get POWs to spill what they knew. The prisoners were subjected to a ‘phoney’ interrogation. Then, back in their cells and rather irritated by the incompetence shown during the interrogation, they would brag to each other about what they had not told their interrogators, little realizing that there were hidden microphones. These were connected to an M Room (‘M’ for ‘miked’), where secret listeners worked in 12-hour shifts, recording the conversations.

There was no easy or quick way of gleaning intelligence from prisoners. Throughout the war, it would remain a question of patiently gathering snippets of information to build a bigger picture of the enemy. Kendrick knew that the steady, painstaking, methodical collection of data – which was to increase with the influx of POWs as the war progressed – would gradually yield results. The results of the listening programme in September and early October 1939 were disappointing, partly because the prisoners had little to say, and partly because many of them were U-boat petty officers, who were found not to be as talkative as officers. The bugged conversations at this early stage yielded only fragments of information. But that would soon change.

Secret recordings

In the first two months of the war, the prisoners were primarily U-boat survivors, with the first German air force prisoners only arriving towards the end of October 1939. There were two U-boat prisoners, brought to the Tower on 1 October 1939, who believed that they had successfully deceived their interrogators, boasting repeatedly to one another in their room: ‘Herrgott, was haben wir die verkackert!’ (‘My God – what shit we served them up!’). Kendrick wrote that he found them ‘crude and incapable of deceiving anyone’.18

Occasionally a prisoner evinced some suspicion. Petty Officer Hochstuhl was overheard to say: ‘I don’t trust the quietness of it here . . . They will use all sorts of means here to get information out of us. I think it is despicable when they put English officers into German air force uniforms.’¹⁹ Clearly, he suspected the British of using ‘stool pigeons’ – British officers masquerading as German prisoners to guide private conversations in a particular direction. Although it was never admitted, Kendrick did indeed use stool pigeons, a technique used in the First World War with which Kendrick would have been familiar.²⁰ As the war progressed, he would use Czech refugees as stool pigeons, as well as deserters, German Jewish refugees and German prisoners willing to operate against Germany, because they no longer believed in the German cause.²¹ The names of most of the stool pigeons used in the war have not been released; however, one of those used in the Tower was Brinley (Brin) Newton-John, the father of British-Australian actress Olivia Newton-John;²² Ernst Lederer, a Czech refugee and grandfather of comedienne Helen Lederer, was another (although later, at Trent Park in north London).²³

Kendrick already had over two decades of expertise in HUMINT, gathering human intelligence. His life in Vienna in the pre-war period had taught him the value of befriending persons who could provide valuable intelligence. The POWs coming through his wartime unit were no different; and if a prisoner was believed to have a large amount of valuable information, he could find himself being accompanied on a nice trip to the theatre, cinema or lunch in central London by a member of Kendrick’s team. This was as much about ‘political deconditioning’ as it was about using blandishments to loosen a prisoner’s tongue: he could observe for himself that London was functioning well, with plenty of goods on sale in the shops. This revelation would undermine Third Reich propaganda that Britain was short of supplies and on the verge of surrender. Or, in another technique, a British officer might talk about politics to try and gauge the prisoner’s opinions on certain matters. This might cause the prisoner to give something away inadvertently. A prisoner’s disillusionment with the Nazi regime might only be temporary, but it was usually long enough for an interrogator to gain the information required.24

One of the most remarkable pieces of intelligence recorded in the M Room at this early stage of the bugging operation came on 28 October. As Kendrick wrote in his summary for that day: ‘They [the prisoners] think the war will end when the Führer comes out with his secret weapon.’²⁵ At this stage, it was not known what the secret weapon was – or indeed whether the prisoner merely hoped that Hitler would come up with a super-weapon that would win the war for Germany. Subjects discussed by prisoners at this time included the synthetic fuel used in German aircraft, combat reconnaissance tactics, torpedoes, the manufacture of Heinkel and Junkers aircraft, U-boat production and U-boat strength and losses. This last topic of conversation was particularly helpful, as it was difficult for Britain independently to verify the number of operational U-boats and the strength of the German navy.²⁶ By the end of January 1940, prisoners were unwittingly divulging information about the testing of new aircraft at Travemünde, on the Baltic coast. One prisoner exhorted his comrades: ‘They [the British] mustn’t find out anything about it and we mustn’t talk about it in the camp. It is still being kept dark, even in Germany.’²⁷ Needless to say, the secret listeners pounced on this with glee and sent the information to various departments, most especially the Air Ministry. The intelligence gleaned and a more detailed account of the bugging operation in the Tower are discussed in my book The Walls Have Ears.28

While Kendrick and his team were successfully harvesting information from the POWs in the Tower, a disaster was about to beset SIS on Dutch soil. This would have serious ramifications for the whole SIS network across Europe, and would mean that Kendrick’s operation back in Britain gained fresh urgency.

The Venlo incident

In mid-October 1939, Richard Stevens, Kendrick’s colleague and the British passport control officer in The Hague, was approached by German army officers who hoped to instigate a coup in Germany and bring down Hitler.²⁹ If successful, they wished to negotiate with the British government. It is now clear from declassified files that ‘C’, the head of MI6, was involved behind the scenes, and that the negotiations involved SIS. ‘C’ made it clear that, if the coup succeeded, the British government would be prepared to consider peace proposals, as the British had ‘no desire to wage a vindictive war’. In return, the government would require some kind of autonomy for the Czechs and the restoration of Poland.³⁰ The two figures who acted as intermediaries abroad were Stevens and his SIS colleague Sigismund Payne Best. Both men were working for Dansey’s Z Organisation and were reporting to him on clandestine negotiations with the anti-Nazi officers organizing the coup against Hitler.³¹ Colonel Teichmann reported that ‘only a small impetus was required to set the ball rolling and get rid of the Nazis’.³² Clandestine meetings were set up on the Dutch–German border, but frequently had to be rescheduled.

On 9 November, ironically the anniversary of Hitler’s attempted putsch in Munich in 1923, and also the first anniversary of Kristallnacht (‘The Night of Broken Glass’, which had seen the windows of synagogues and Jewish businesses smashed across the Third Reich), Stevens arrived at Venlo with his colleague Payne Best. But the whole thing was a sting operation. They were met by unknown Gestapo men and arrested. Payne Best was originally thought to have been fatally shot, along with their driver Dirk Klop. But in fact he was still alive. He and Stevens were taken to Gestapo headquarters in Berlin and interrogated, before being transferred to Sachsenhausen concentration camp. Stevens was later transferred to Dachau; Payne Best went to Buchenwald and then Dachau. They survived the war.

The Venlo affair was the most serious catastrophe to befall SIS since its foundation and the repercussions would be felt for years to come. What is not clear is how much information Payne Best and Stevens gave up in interrogation; but SIS certainly feared and believed that its whole network in Western Europe had been compromised. This blindsided SIS, because it could not verify how much the Germans knew about its agents and operations. In retrospect, it would appear that Payne Best and Stevens only gave away the names of those involved in the Z Organisation network (leaving SIS otherwise unscathed), but SIS did not know that. Kendrick’s name subsequently appeared on the Black Book’s list of names of those who were to be rounded up following a German invasion of Britain.

The Venlo affair was a real failure of professionalism, especially on the part of Kendrick’s colleague Claude Dansey, head of the Z Organisation, of which Payne Best and Stevens were members. Venlo badly damaged the unique position of SIS in Britain – for reasons that relate to the intense rivalry between SIS and MI5 (Britain’s security service responsible for security on British soil). Historically, SIS – like its parent, the Foreign Office – recruited mainly from certain exclusive public schools in the UK and from the universities of Oxford and Cambridge. Its objective was to create sources to provide the best intelligence from abroad so as to defend the realm; it was therefore not interested in seeking justice, and it used questionable people with suspect backgrounds. MI5, on the other hand, was all about security and therefore was made up primarily of police officers and non-senior army officers. Some of its staff were recruited from private schools – but not the same ones that supplied SIS. MI5’s brief was to bring to justice anyone who threatened the realm from inside the borders of the UK. And although SIS and MI5 worked together up to a point, there was intense hostility and different emphases.

Within six months of Venlo, Britain had a new prime minister, Winston Churchill, who was prepared to countenance a new type of foreign intelligence and operations – ungentlemanly warfare – which broke the mould of the public-school ethos. By 1942 – albeit under pressure from Labour coalition members – he had sanctioned the creation of the Special Operations Executive (SOE). Because of Venlo, SIS and SOE, as well as the new branch of military intelligence MI9, tried to function independently, especially in their escape lines during the Second World War.33

How could the British secret service survive the catastrophe of Venlo?

The answer was to be found nearly 350 miles away, in north London. Kendrick had just requisitioned an estate near Cockfosters and was about to expand his eavesdropping operations. The Combined Services Detailed Interrogation Centre (CSDIC) at Trent Park would allow him to process far more enemy prisoners. The rather clunky name of this unit obscured its real purpose: it was to become the biggest bugging operation ever mounted against an enemy of Britain. Kendrick would go on to orchestrate the greatest deception against Hitler’s generals – a slow subterfuge that would ultimately help shorten the war and enable SIS to survive Venlo.