The Codebreakers: The True Story of the Secret Intelligence Team That Changed the Course of the First World War

by James Wyllie

  Not that he was a soft touch, far from it; a strict disciplinarian with hawkish features, he could be terrifying if he wanted to be. The nickname ‘Blinker’ came about because of a persistent twitch. What is striking in the testimony of those who knew him is how little this featured in their recollections. In others the twitch might have been taken as a sign of weakness and anxiety; not in Hall’s case. Instead, what struck his colleagues about his piercing blue eyes was the effect they had when he trained his laser-like stare on you: once trapped by his unyielding gaze, it was impossible to escape the feeling that he was reading your mind. As Walter Page, US ambassador in London, observed, ‘Hall can look through you and see the very muscular movements of your immortal soul while he is talking to you.’

  Admiral Sir Reginald Hall, as commander of HMS Queen Mary, 1914

  As war approached, Hall was ready and eager to test the Queen Mary in battle. On 28 August, he was part of the squadron, under the command of the young firebrand Admiral David Beatty, which went to the aid of destroyers being harassed by enemy submarines and cruisers near the Heligoland Bight, the heavily mined exit point for the German fleet. During a brief engagement, two German ships were sunk.

  This skirmish proved to be the last action he saw. Throughout his life he’d been plagued by a weak chest and bronchial problems that were aggravated by cold and damp weather. Given his current hunting ground was the North Sea, no stranger to freezing winds and driving rain, his condition soon became serious. On 10 September, Beatty noted that ‘Captain Hall is far from well, he looks terribly grey and tired’.

  Beatty was not the only one concerned for Hall’s health. Ethel Agnes, Hall’s wife, was so worried that she wrote to Admiral Oliver, who had just stood down as DNI to become Churchill’s assistant, begging him to find her husband a desk job. Oliver obliged, and Hall took over as Director of Naval Intelligence. His frustration at being denied the chance to end his career at sea evaporated as he found himself at the helm of the good ship Room 40, and he proceeded to build an intelligence empire that spanned the globe.

  In his unpublished autobiography, Hall explained his approach to the job, revealing a subtle grasp of human psychology and the need for flexibility: ‘a Director of Intelligence who attempts to keep himself informed about every detail of the work being done cannot hope to succeed; but if he so arranges his organisation that he knows at once which of his colleagues he must go to for the information he requires, then he may expect good results. Such a system, moreover, has the inestimable advantage of bringing out the best in everyone working under it, for the Head will not suggest every move; he will welcome, and indeed, insist on ideas from his staff.’

  The main criticism levelled at Hall by his colleagues was that he was too fond of intrigue. Without doubt, he relished devising elaborate ways to deceive the Germans and often made risky and hasty decisions. His secretary called him a gambler who enjoyed a dangerous game, and recognised the Machiavelli in him. Underneath, however, was nothing but a schoolboy; she fondly remembered how ‘the fun and hazard of it all would fill him with infectious delight’.

  Of all the intelligence chiefs, Hall exercised the most authority because he was able to escape the confines of his department. No door was left unopened, no area of policy neglected, no aspect of the war untouched. As a result, all roads led to him: Guy Gaunt, Hall’s man in the USA, realised ‘what a powerful friend he was … when I saw the men who came quietly into his office. I think I saw most of the cabinet, and for that matter, everybody else in England of any note.’

  Hall’s unique position owed a great deal to his forceful personality. However, it was the intelligence supplied by his codebreakers that justified his ubiquitous presence in the corridors of power. Credit goes to him for the way he marshalled this eclectic band of civilians, but it was their talent, ingenuity and perseverance that granted him the keys to the kingdom.

  It was Churchill, as civilian head of the Admiralty, who laid the procedural and institutional basis for Room 40. Realising the immense advantages the codebreakers could provide, and equally aware that these would be rendered redundant if the Germans suspected that their communications were compromised, Churchill drew up a charter that guaranteed absolute security: the wireless intercepts were to ‘be written in a locked book with their decodes, and all other copies are to be collected and burnt. All new messages are to be entered in the book, and the book is only to be handled under the direction of the Chief of Staff’, a position occupied by Admiral Henry Oliver, a rigid workaholic who often did a 150 hour week; he was nicknamed ‘the Dummy’ because of his lack of facial expressions and monosyllabic utterances. Oliver would then circulate the decoded material to a handful of high-ranking naval personnel.

  The Old Admiralty Building, Whitehall, home to Room 40

  While this degree of caution was understandable, it was not particularly practical and it placed Room 40 in a straitjacket that was hard to struggle free from, delaying its growth into a fully fledged, proactive intelligence organisation. However, in its chaotic early days, this was the least of Room 40’s problems as it stumbled into being.

  Much of what we know about this period of Room 40’s life comes from one of its first recruits, Alastair Denniston. Born in 1881, Alastair’s father was a doctor who died of TB when he was ten. After performing well at school, he studied abroad, first at the Sorbonne in Paris and then at Bonn University, giving him a thorough knowledge of German, followed by a stint teaching languages at a school in Edinburgh and later at the Royal Naval College on the Isle of Wight: all ideal preparation for life in Room 40.

  His pre-war claim to fame was as an athlete, playing in the Scottish hockey team at the 1908 London Olympics. The opening match took place on 29 October at Shepherd’s Bush Stadium in atrocious conditions and pitted Denniston’s Scotland against Germany. After winning the match 4–0, Scotland then faced England in the semi-final, played on the same day. The old enemy thrashed them 6–1 and went on to win gold by beating Ireland 8–1 in the final. A third-place play-off for the bronze medal between Scotland and Wales was abandoned after the Scots went home that evening; a historian of the sport concluded that ‘the Scotland players had to get back to work’. In the end, a compromise was reached: both teams were awarded bronze and Denniston became the proud owner of an Olympic medal.

  Alastair Denniston, one of Room 40’s earliest recruits

  When Denniston joined Room 40, it only had five other staff. All of them, according to him, were ‘singularly ignorant of cryptography’. Isolated from their boss, they had to carry their results down the corridor to his secretary. By November, this small group were installed in Room 40. Their new home was on the first floor of the Old Admiralty Building in Whitehall. Tucked away, quiet, with a view over an inner courtyard, its discreet location compensated for the cramped conditions.

  A shift system was organised: two staff on duty between 9 a.m. and 7 p.m., then one on night watch, all engaged in the business of translation, sorting and decoding. Initially messages were brought by a ‘never ending stream of postmen delivering bundles’, then by pneumatic tubes (originally developed to speed up the exchange of telegrams between businesses), ‘which discharged goods into a basket with a rush that shook the nerve of any unwitting visitor and much disturbed the slumbers of the nightwatchman’.

  Night duty in those first few months was a lonely time. There were no washing facilities and it was ‘no good bringing pyjamas’. Instead, the night shift consoled themselves with ‘plenty of sandwiches’.

  Intercepted German wireless transmissions would provide Room 40 with the bulk of the material it analysed. This relatively new technology was available to the navy through its close contacts with the Marconi Company. Before August 1914, it already had wireless telegraphy (WT) interception masts at sites in Stockton, Chelmsford, Dover and London, plus access to Marconi’s stations, and had begun to pick up German communications; in the opening days of the war, a steady stream began to accumulate.<
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  Considering the secrecy shrouding Room 40 – only a handful of top brass knew of its existence – it’s hardly surprising that nobody thought to provide it with the messages that were coming in. Instead, it took the intervention of two well-heeled amateur radio enthusiasts to join the dots and connect Room 40 to its key source of intelligence.

  Very few people in Edwardian England had the resources needed to own or construct a wireless set; those who did formed a socially exclusive club of hobbyists tinkering with primitive valves, amps and transmitters. One of these was Russell Clarke, a barrister, who began obtaining German intercepts. Quick to grasp their importance, he approached Sir Alfred Ewing, titular head of Room 40, and offered his services.

  This was a fortunate chain of events, given the regulations laid out in the Defence of the Realm Act (DORA), which placed a plethora of restrictions on citizens’ rights, including the right to own a radio. Police forces across the land were ordered to ensure that no domestic wireless appliances remained in operation. Quite how Clarke evaded these conditions is unclear; Denniston speculated ‘that some rash official had tried his best on Russell Clarke and had been forced to retire worse for wear’. Clarke was soon joined by another radio ham, Bayntun Hippisley, who had also picked up signals ‘obviously of Hun origin’. Clearly there was a rich seam to be mined, and interception apparatus was installed at Hunstanton coastguard station in Norfolk.

  Clarke soon realised that ‘he could intercept hundreds of … messages daily on short waves, which, if read, would give the daily doings of the German Fleet’. But Room 40 was still unable to make sense of them. Then the gods smiled on the codebreakers, not once but three times.

  At 00.14 on 26 August, the Magdeburg, a German battle cruiser patrolling the Baltic, ran aground. Her captain ordered the destruction of two of her three copies of the Signalbuch der Kaiserlichen Marine (the Signal Book of the Imperial Navy), or SKM, leaving one available if they needed to signal for help. However, explosive charges that were meant to scuttle the vessel went off prematurely, and the crew began to abandon ship before the code books had been dealt with. At 04.10, the Russians showed up, and after three hours of inconclusive skirmishing, it was all over.

  All three copies of the SKM were retrieved by the Russians, one from the ship and two from the sea. Exactly how this was done has never been conclusively established; Churchill, always ready to use poetic licence when the facts were lacking, wrote that ‘the body of a drowned German … was picked up by the Russians a few hours later, and clasped in his bosom by arms rigid with death, were the cipher and signal books of the German navy’.

  The SKM was an immense tome containing 300,000 three-letter codes, each one referring to a plain-language word, phrase or name. Its covers were lined with lead, making it too heavy to hold in your hands. It had been in use for some time, pre-dating wireless, and included all forms of signalling employed by the fleet – flags, lamps and semaphore. Wireless codes, added later, were divided into sections featuring lists of ships, place names, compass bearings and map grid references.

  The Russians understood the significance of the SKM. Knowing that the British navy would profit handsomely from it, they entrusted a copy to the son of the Russian ambassador in London, who gave it to the Admiralty on 13 October.

  The next stroke of luck came courtesy of the Royal Australian Navy. On 11 August, they interned a German merchant ship in Melbourne harbour. On it was a copy of the Handelsschiffs Verkehrsbuch (HVB), a signal book that used four-letter codes. A month later, this copy was forwarded to the UK, arriving at the Admiralty in late October. Denniston recalled how Room 40 soon discovered that the HVB was used by the whole German fleet, including its submarines and airships.

  The final find occurred during November, when British trawlers working in the neighbourhood of the spot where four German destroyers had been sunk close to the Dutch island of Texel, recovered a code book used by the German Admiralty and senior officers. The Verkehrsbuch (VB), which contained 100,000 code groups, each consisting of five numbers, was used for correspondence with the naval attachés abroad, especially in Madrid, where the German embassy was orchestrating sabotage and subversion across the Mediterranean and North Africa.

  Thanks to this ‘magnificent draft of fishes’, as the haul was dubbed, Room 40 staff now had the means to decode everything the Germans said. They were helped immensely by the German reaction to these potential security breaches. On the day after the sinking of the Magdeburg, its squadron commander admitted that it was not known whether the SKM had been destroyed. However, an official hearing convened in September concluded that there was no evidence that the Russians had got hold of it. Prince Henry of Prussia, commander of the Baltic fleet, wasn’t so sure. He thought it was ‘probable’ that the Russians had recovered one of the signal books. Nevertheless – and incredibly – the SKM was not replaced until May 1917.

  Not long after the Australians took possession of the HVB, the governor of German South-West Africa and various cruisers roaming the South Atlantic were informed that the book was compromised. Despite this warning, nothing further was done and the HVB stayed in use until 1916. As far as the VB was concerned, it never occurred to anyone that it might have fallen into the lap of the enemy, and it too was kept in operation until 1917.

  The Germans’ inadequate and lethargic response to these incidents, coupled with the arrogant assumption that their codes were infallible, cost them dear. Room 40 had ample time to thoroughly familiarise itself with the habits, movements and intentions of the enemy’s battleships, U-boats and Zeppelins, while their networks of spies, conspirators and terrorists were similarly exposed. By the time the books were finally replaced, the British codebreakers had become so adept and experienced that they were able to tackle them head on.

  Chapter 2

  BATTLE STATIONS

  At around 8 a.m. on 16 December 1914, two ships from a squadron of German battle cruisers under the command of Admiral Franz von Hipper opened fire on the Yorkshire resort of Scarborough. At the Grand Hotel overlooking the sea, one of the guests was shocked awake by ‘a tremendous noise’ and ‘looked out of the window and saw a huge flame and clouds of smoke’. As shells crashed into the town, thousands fled their homes and headed for the railway station. Half an hour later, the bombardment was over, leaving 12 dead – including a postman blasted to smithereens while delivering mail – 99 wounded, and churches, public buildings and homes reduced to smouldering ruins.

  At roughly the same time, Hartlepool, an industrial town with a busy dockyard, 65 miles to the north of Scarborough, also came under fire from German ships. More than 300 houses were damaged, with 86 civilians killed and 424 wounded. An hour later, Whitby, 20 miles north of Scarborough, suffered a 10-minute bombardment and the loss of two lives.

  Forty-eight hours earlier, Room 40 had picked up indications that the Germans were up to something. For the very first time, the codebreakers would have a major influence on the planning and tactics of a naval operation. According to First Lord of the Admiralty Winston Churchill, decoded messages suggested ‘an impending movement which would involve battle cruisers, and perhaps … have an offensive character against our coasts’.

  At this point, Room 40 had received no indication that the bulk of the German High Seas Fleet, under the command of Admiral Friedrich von Ingenhol, was also going to be involved in the operation. As a result, only sufficient forces to deal with Hipper’s battle cruisers were put out to sea. This was a mistake. The German High Seas Fleet was indeed following in the wake of Hipper; it was to play a supporting role, either by offering assistance or by pouncing on any British ships that strayed across its path. However, a few hours before Hipper reached his targets, Ingenhol received information that the British were also on the move, and promptly turned his ships round and headed back to base.

  Nevertheless, the codebreakers had still created an opportunity to catch Hipper unawares. To retain the element of surprise, no attempt was made to preve
nt the raids from being carried out. After all, if the British were ready and waiting, the Germans might suspect that their codes had been broken. Instead, the British cruiser force was to lie in wait for Hipper as he made his return journey. Due to poor weather and the confusion it caused, however, they were unable to engage him and he slipped safely back to Germany.

  Though the Admiralty was disappointed that Hipper had escaped unscathed, and deeply embarrassed by the public’s justifiable outrage at its failure to defend the coast, Room 40 had proved its worth. Churchill drew comfort from the fact that ‘the indications upon which we had acted had been confirmed by events. The source of information upon which we relied was evidently trustworthy.’

  The challenge facing Room 40 and the Royal Navy in 1914 was shaped by one of the great strategic military follies of the pre-war period, or indeed any period: the Kaiser’s quest to build a fleet to rival the Royal Navy. A lover of all things nautical, he jealously eyed the mighty British fleet and wanted one of his own to play with. Exactly what purpose his navy would serve, beyond satisfying his childish impulses, was not clear. More than anything else it convinced the British that the Germans were out to get them, and they responded in kind with their own massive building programme, which included constructing the biggest, most powerful warships the world had ever seen, the dreadnoughts, whose weight of fire was sufficient to wipe out any other vessel in existence thereby forcing the Germans to do the same.