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

by James Wyllie

  Unperturbed, Gill pressed his case. Finally it was agreed that a test shoot would take place. All the inhabitants of the island were warned in advance. This only served to cause the panic they were hoping to avoid, and the population promptly fled to the hills. To cap it all, when the firing took place, the recoil buried the gun in the earth.

  Gill’s last mission in the area was to set up a DF station on the island of Mudros, home to a small naval base manned by Royal Engineers ‘who were commonly reputed to spend all their time building fresh piers for the navy to land beer on’. The staff at the local HQ thought it should be built on a hill on the far side of the island. Gill pointed out that ‘in actual fact a DF station requires a fairly level bit of ground’ and found a better location near the naval camp. HQ thought this was too close for comfort. Gill persisted and got his way.

  Once up and running, the station operated 24 hours a day. However, at night, the island was blacked out, which presented a problem for the DF operators: how to ensure they had enough light to do their job without standing out like a diamond in a pile of coal. Their solution was to use an electric lamp covered by a shade made out of red chocolate wrapper. Unfortunately, the first night they used it, pandemonium broke out on the British flagship moored nearby, the sailors going into frenzied preparations for action because ‘showing of a red light was the alarm that a Zeppelin was on its way and some enterprising sentry had seen our chocolate paper’.

  Despite the absurdities encountered by Gill, his work paid dividends as the volume of intercepts available for analysis by Room 40 increased daily. Nevertheless, Hall felt more could be done. Up to this point, he had jealously guarded his codebreakers and their secrets from the other Allies. But the U-boat crisis demanded a more collaborative approach. The French Admiralty, who had overall responsibility for the Mediterranean, were given the privilege of seeing Room 40’s intelligence summaries, carried by messenger to Paris every night.

  Next Hall turned his attention to Italy. Its cryptographic operation was primitive by comparison, so he decided to send one of his star codebreakers, Nigel de Grey, to assist them. Fresh from his Zimmermann telegram triumph, de Grey managed to solve the Austrian and German naval ciphers used in the region by the summer of 1917. Armed with this knowledge, and accompanied by half a dozen codebreakers and several wireless engineers, he headed for Italy.

  His first move was to have a wireless interception station erected at Otranto. Two more listening posts were established in Rome and Brindisi. A series of DF stations was added to the mix. With this infrastructure in place, de Grey ran the NID in Rome until the end of the war. Supported by nine officers, four female clerks and 15 naval personnel working closely with his extremely grateful Italian counterparts, he masterminded a dramatic improvement in their intelligence-gathering, limiting the U-boats’ freedom of movement and strike capability.

  The increase in U-boat casualties offered Hall the chance to ease the burden on his codebreakers. During 1917, the Germans had changed the SKM, their main naval code book. Without a physical copy of the new codes, Room 40 had to start from scratch. The job was made somewhat easier by the U-boat wireless operators. Faced with a more complex code, which was therefore trickier to transmit, they often, through laziness and force of habit, stuck with the old version. At the same time, Dilly Knox, who was single-handedly spending every waking moment trying to find a way into the new system, was making good progress. The codes were being painstakingly reconstructed from the ground up.

  Even so, it would make a huge difference if Room 40 could obtain a copy of the book. An obvious place to look was in the carcasses of U-boats. Hall assembled a team of expert divers and gave them explicit instructions about where to find the sunken treasure: ‘open torpedo hatch, open five water-tight doors, turn sharp to right and retrieve top drawer in which were all papers’.

  E. C. Miller, Hall’s most effective diver, explored the remains of 25 U-boats. It was a grisly business. Aside from the eerie atmosphere that haunted these ghost ships, Miller had nature’s predators to contend with as they feasted on the crew’s corpses: ‘the dog fish are always about and will eat anything. In the mating season they naturally resent any intruder, and on lots of occasions when … I offered them my boot … they never failed to snap at it … I found scores of conger eels, some seven feet long … all busily feeding.’

  On one mission, Miller recovered documents from a U-boat, sunk near Dover, which showed the Germans had broken the code used by British minesweepers. Rather than change the code, Hall decided to deceive the enemy. Knowing that it would be picked up by the Germans, he had a message sent declaring that a particular minefield off the Irish coast, which in reality was still active, had been swept clear. This false information was enough to lure a U-boat, UC-44, into the area, where it promptly hit a mine and sank. Miller then dived down to the wreck and found a copy of the new code book. Hall’s gamble had paid off and Room 40 were quickly up to speed.

  Overall, this unprecedented mobilisation of the manpower, technological know-how and weaponry available to the Allies shows how seriously they took the U-boat menace. At the heart of this effort was Room 40. William James, its naval representative, was not exaggerating when he wrote that ‘without Room 40’s information the defeat of the U-boat would have been more difficult and more prolonged’.

  Chapter 18

  DESERT CODES

  During 1917–18, U-boat attacks in the Mediterranean took on special significance for the British army. Not only were much-needed troops and supplies – funnelled up the Suez Canal from the Indian Ocean – crossing the Mediterranean in order to reach the killing fields of the Western Front, they were also going the other way to join the forces engaged in desert warfare. The British were attempting to bring the Ottoman Empire to its knees by driving the Turks out of Palestine and completing the conquest of Mesopotamia (Iraq). Malcolm Hay’s codebreakers in London, and their associates in the Middle East, provided invaluable and, at times, decisive assistance, both strategically and tactically.

  One of MI1(b)’s priorities was to help reverse the disastrous failure of the British Indian army, known as D Force, in Mesopotamia. D Force was the creation of the India Office, which ran the subcontinent and its military policy. It resented any interference from London, and was engaged in a fractious rivalry with the administrations in Cairo and Khartoum. It saw the German-sponsored jihad – an attempt to rouse the Muslim masses living in the British Empire that was backed by the Turks and combined propaganda, sabotage and guerrilla warfare – as a grave threat to the Raj, and decided a show of strength was required to neuter it. Initially the goal was limited to securing the Persian Gulf, where Britain already had a coastal presence, thereby protecting the trade route to India and the oil recently discovered there.

  Landing on 6 November 1914, D Force occupied Basra on the 21st. Moving slowly up the narrow, mosquito-infested Tigris River, they engaged Turkish troops at Qurna and won easily. By the summer of 1915, when campaigning was suspended because of the heat, the army’s ultimate objective was still not clear. On 23 October, after General Townshend had deployed near the city of Kut, the Cabinet in London approved an advance on Baghdad, some 100 miles away, despite the fact that D Force’s supply lines were already stretched to breaking point.

  The Turks were waiting upstream in fortified positions with a force twice the size of Townshend’s. The two sides clashed at the Battle of Ctesiphon, 25 miles south-east of Baghdad. Though D Force edged the contest, it was badly bruised. Having sustained 10,000 casualties so far, Townshend decided to withdraw and headed for Kut, which was quickly encircled by the Turks.

  The siege of Kut lasted nearly five desperate months; food and water dwindled to nothing, disease was rife. At the end of April 1916, Townshend decided to surrender. The 3,000 British and 6,000 Indian soldiers taken prisoner were marched hundreds of miles and deposited in camps where the conditions were appalling: few survived the ordeal. Townshend saw out the war in relative
comfort near Constantinople.

  The fall of Kut was a serious blow to British prestige. This humiliating defeat coincided with a significant shift in attitude in London; previously the British authorities had been reluctant to commit too many men or resources to the Middle East, but David Lloyd George, the leader of a new coalition government, was keen to extend British influence in the region.

  Even before the war, many considered the Ottoman Empire to be on its knees: all it would take was a gentle nudge to topple it over. The strength and determination of the Turkish resistance during the tortuous, ill-fated Gallipoli expedition seemed to suggest otherwise. Yet the idea persisted that the Ottoman Empire would not survive the war.

  This concentrated minds on the fate of the non-Turkish areas of that empire, and who would control them. Both British and French imperialists had ambitions in that direction. France coveted Syria and the Lebanon. Aside from Mesopotamia, Britain had its eyes on Arabia and Palestine. Their respective spheres of influence were formalised in the secret Sykes-Picot agreement which was signed in May 1916. The Egyptian Expeditionary Force (EEF), based in Cairo, was to be made ready to launch an offensive with Palestine as its primary target.

  Up to then, its role had been defensive; its priority to protect the Suez canal, the main artery of Empire. Its only taste of action thus far had come in early 1915, when a modest Turkish force, having crossed the Sinai Desert unscathed, attempted to seize the Suez Canal. However, they were no match for the entrenched guns of the EEF. Though Turkish commanders still nursed a desire to try again, this did not translate into action. Now that a major campaign was being planned, good wireless communciations were required and Eric Gill, the wireless wizard, was the right man for the job.

  Gill arrived in Cairo and after spending several fruitless days scouting for a location to erect a wireless mast, he ended up taking a trip to see the Pyramids. Once he caught sight of these ancient monuments to the glory of the Pharaohs, he realised he’d found what he was looking for. The peak of the Great Pyramid was the perfect spot for a wireless receiver/transmitter. Once attached, it had an impressive range; as Gill noted, ‘the aerial turned out to be extremely efficient. With a single valve receiver a Zeppelin over England was heard by it.’

  Duties accomplished, Gill remained in Cairo, where, for lack of anything better to do, he and a colleague began trying to tackle some of the messages coming in. Given that British intelligence in Egypt did not yet have a dedicated cryptographic section, all intercepts were being sent to Malcolm Hay’s team at MI1(b) in London, which was making good progress with the enemy’s Middle Eastern codes. Hay decided it was time to put the Egyptian operation on a proper footing. An expert was sent from London, identified by Gill in his memoirs as simply ‘Mr Inductance’, to train up and advise the locals. This mystery man was none other than Oliver Strachey.

  When Strachey arrived in Cairo, the city had a reputation as a party town. Boozy expats and colonial staff combined their English pastimes with more exotic pursuits. At night, the streets were filled with increasing numbers of rowdy and riotously drunk soldiers, many of them Australian. Though Strachey didn’t have much in common with either of these groups he would have found ways to enjoy himself.

  Strachey had no problem imparting his wisdom to Gill, but was driven to distraction by an officer who’d arrived from HQ in Salonika, which was jealous of the special attention given to Cairo. This officer knew no German at all, worked in accounts and had ‘never taken any interest in ciphers, puzzles, crosswords … or anything of that nature’. He was quickly sent packing ‘by the next boat’.

  The knowledge Strachey brought with him had been hard won. An initial way into the German—Turkish codes was provided when a cipher used by the Turks in Yemen was found on board a captured boat. It provided useful clues about how to tackle the others. In mid 1916, MI1(b) obtained a copy of the primary Turkish code book. Lax behaviour by the German wireless chief in Constantinople provided further insights. According to Gill, after a celebration dinner to mark his return from Berlin this man sent messages of ‘good cheer to all enemy stations in six different ciphers. Before this happened five of the ciphers were undecipherable by us but we knew the sixth. After … we knew the lot.’ The Turks were ‘even more delightful, as frequently they did not bother to encipher their messages at all’, and had a ‘habit of chatting to each other when business was slack’.

  MI1(b) attacked the material and identified the ciphers used to foment trouble in Persia, Afghanistan and Arabia. Other ciphers dealt with tactics, the flying corps, administration and supplies. The only one that eluded them governed messages to and from the German High Command in the region: known as the Yilderim cipher, it took nearly a year to solve.

  In the spring of 1917, Strachey set off for home. Near Cyprus, his ship was spotted by a U-boat and sunk by its torpedoes. Strachey, and the others who managed to get off the boat before it hit the bottom of the sea, was eventually rescued by the navy. He treated the whole incident as nothing more than a minor inconvenience.

  While the EEF prepared to go into battle, steps were being taken to salvage the honour of the British army in Mesopotamia. A much larger and better equipped force was assembled by the War Office, and a new commander, General Maude, was furnished with 150,000 men, substantially more aircraft and, for his advance up the Tigris and Euphrates rivers, 446 tugs, compared to the mere 14 available to Townshend’s doomed mission.

  Indian sappers lay telephone cable during the Mesopotamian campaign of 1917

  General Maude would also benefit from more accurate intelligence about his enemy. Inadequate intelligence had dogged Townshend from the start. Although the India Office was the first government department to set up a dedicated cryptographic bureau in 1906, it concentrated on Russian codes – the tsar’s empire was considered to be the most serious threat to the Raj – and did not feel the need to examine German or Turkish ones. Even if it had, any advances made would have been undermined by the lack of material to work with: in the early stages of the war, the Turks rarely used wireless, instead relying on telephone. During 1915, they laid 2,000 km of landlines while possessing only three fixed wireless stations, none of which was in Mesopotamia. This left D Force at the mercy of local agents who were often unreliable and self-serving, and had a tendency to tell the British what they wanted to hear.

  Consistently lacking was accurate information on the size and composition of enemy forces. D Force overestimated the number of soldiers it encountered in the initial actions, thus leading to overconfidence, and underestimated them when it came to the critical showdown at Ctesiphon. This dire situation would be rectified thanks to intelligence officers with the necessary talents and intellectual training to successfully penetrate the enemies’ codes, aided by a powerful wireless transmitter/receiver that had been erected in Basra, and by the fact that the Turks had by then established half a dozen wireless stations in Mesopotamia, thereby providing the codebreakers with enough material to work on.

  The two codebreakers who helped guide Maude to victory were Gerard Clauson and Reginald Campbell Thompson. Clauson was born in 1891 and educated at Eton, where he displayed a talent for languages. Aged 15, he taught himself Turkish. At Oxford he studied classics and then began an academic career, winning prizes for translations from Sanskrit while conducting research into the Turkic family of languages, picking up Mongolian and Tibetan along the way. During 1915, after a spell on the Gallipoli front, he joined D Force.

  Reginald Campbell Thompson was 15 years Clauson’s senior and represented a select breed of intelligence officer: the archaeologist. As a child he collected flints and bits of Persian pottery, and by his teens was translating ancient Assyrian texts from their original cuneiform script. The earliest known system of writing, cuneiform was made up of symbols carved into clay tablets. Developed by the Sumerians, it remained in use for thousands of years, growing in sophistication as it passed through the Babylonian, Assyrian and Hittite civilisations. The art
of reconstructing and deciphering cuneiform from archaeological fragments was the perfect training for work as a codebreaker.

  After studying Oriental languages at Cambridge, Thompson embarked on nearly 20 years of wandering the Middle East, moving from one excavation project to another, collecting and then recording his finds in a series of books that included trailblazing studies of the magic, demonology and astrology of the Babylonians. Clauson affectionately described him as a ‘curious old bird with a most amazing inverted brain’. Clearly Thompson had an unusual mind. He liked to visit the cinema because ‘he solved many of his hardest problems as he watched pictures floating across the screen’. But he was also a man of action; more Indiana Jones than Nutty Professor. He was a crack rifle shot and an accomplished sailor. He regarded exercise as a ‘moral obligation’. He had little patience with those lacking the physical toughness to endure the rigours of field work in harsh and hostile landscapes, believing a man should be able to withstand ‘heat and cold, hunger and thirst’.

  In 1904, on his way to a site in Mesopotamia, he was delayed by ‘a local plague’ and ‘some slight inconvenience caused by a rumour … that an English doctor had been poisoning his patients’. On arrival, he discovered that ‘the texts they had come to recopy were carved on the sheer face of a rock overhanging a precipice’. Thompson, suspended above the ground in a cradle made from packing cases, manoeuvred into place by ropes and pulleys, spent 16 days transcribing and photographing the inscriptions, drawing them with such a steady hand that ‘hardly a tremor can be detected in any stroke or sign’.

  In 1914, he was attached to the general staff of D Force, accompanying Townshend on his doomed mission. Thanks to his local knowledge and well-honed survival skills, he was able to escape the encirclement of Kut and join the relief force battling to get to the city.