The Codebreakers: The True Story of the Secret Intelligence Team That Changed the Course of the First World War (8 page)

Rigorous and pragmatic, he thought that ‘anyone of average intelligence can learn to read cryptograms’, on the basis that ‘every message, every sentence in a message, has its own distinctive pattern, and contains repetitions of letters, of combinations of letters, and sometimes of complete words’, and that these repetitions were especially vulnerable to frequency analysis: observing how often and in what position letters appeared in the text. However much ‘these patterns can be disguised, they cannot be destroyed’.

Hay identified two main methods of disguise: substitution and transposition. In the first, ‘the letters of the text are replaced by various symbols’, usually letters or numbers. In the second, ‘the letters of the text change their position according to some predetermined arrangement, or key’.

The ‘key’, generally known as the cipher key, was composed of numbers or letters, sometimes randomly organised, sometimes not – ciphers often featured names, or common phrases, or snippets from songs or poems – of varying lengths, that were attached to the beginning of the encoded message and determined what arrangement of the alphabet was being used in the rest of the text. Uncovering the formula of the cipher key, a device used by the German navy, its diplomats and secret services, was an essential part of the codebreaker’s work.

The man Malcolm Hay replaced as the boss of the military’s codebreakers at MI1(b) was Brigadier General Francis Anderson, who had successfully analysed the enemy’s ciphers during the Boer War and had written several pamphlets on the subject of codebreaking. Though retired at the outbreak of hostilities in 1914, Anderson didn’t hesitate to offer his services as the Allies fought to withstand the massive German onslaught that the Kaiser hoped would end the war quickly.

Up to that point, although the War Office had recognised the need to develop its cryptographic capabilities, it hadn’t done much beyond publishing a manual and making tentative efforts to examine German army field ciphers. As the BEF arrived in France, it set up wireless interception facilities that soon picked up a vast amount of traffic, both German and French. However, reception was poor and the messages were often garbled and full of errors.

When it came to the vital first few months of the conflict, it would be the French who led the way. Their cryptographic unit, the
Bureau de Chiffre
, had been established in the wake of the Franco-Prussian war of 1870, when the French were humbled by Bismarck’s army, to act as the first line of defence against further aggression. As the Germans massed once again on their borders, the French had ten wireless interception stations ready to receive the enemy’s messages, including one at the top of the Eiffel Tower. The material coming in from these sources enabled the Bureau to break the German codes. So efficient were the French codebreakers that when the Germans introduced a new cipher, it defied the Bureau for only three weeks.

By that time, the Germans’ mammoth offensive had run out of steam. Their exhausted wireless operators, overwhelmed by the sheer volume of material they had to transmit, had resorted to broadcasting
en clair
. The Allies picked up these uncoded messages, giving them the information they needed to repulse the enemy assault at the First Battle of the Marne in early September, and plan the subsequent counter-attack that would drive a wedge between the German armies, forcing them to retreat.

Over the next couple of months, more
en clair
communications warned the BEF about six German attacks as both sides raced towards the French coast. Had the Germans got there first, the BEF would have been stranded, cut off from supplies and reinforcements. Instead, it was able to dig in and establish a defensive line. The Germans did the same. Four years of trench warfare had begun.

At MI1(b), Hay inherited three members of staff, including an unemployed 40-year-old aesthete, Oliver Strachey, who would become one of the key figures in Britain’s codebreaking apparatus. A man of abundant gifts, Strachey lacked the motivation to capitalise on them until he became a codebreaker in 1914 and found his true calling.

A confirmed atheist, he enjoyed life and viewed it as a game not to be taken too seriously. A friend of his daughter described him as ‘gregarious, amused, amusing, highly intelligent, and interested in everything’. His subversive nature is best captured by an anecdote concerning his time as a juror on what appeared to be an open-and-shut case. A well-known robber was being tried for loitering with intent outside a house with a crowbar down the inside of his trouser leg. With the rest of the jury ready to rubber-stamp a guilty verdict, Strachey, out of ‘sheer devilry’, thought it would be amusing to see if he could change their minds ‘by force of logical argument’. Though it took some doing, he persuaded them that the thief was not guilty. Back in court, when the foreman delivered their shock decision, ‘the judge’s mouth fell open – but he wasn’t nearly as surprised as the prisoner’.

Strachey’s non-conformist character owed a lot to his mother, Lady Jane Strachey. A modern woman – she smoked and played billiards – with a passion for literature, liberal politics and feminist causes, she passed on her love of words to her children and encouraged them to let their imaginations run riot. Oliver’s younger brother Lytton found literary fame as the author of
Eminent Victorians
(1918); his sister Dorothy translated the writings of her friend André Gide into English; while another brother, James, would do the same for the works of Sigmund Freud.

Oliver Strachey, leading codebreaker, lost in thought

Educated at Summerfield and Eton, where he excelled at languages, mathematics and music – the piano was his first and most enduring love – Strachey managed to get himself expelled from Balliol College, Oxford, after just two terms. Rumours that he’d had a homosexual affair were dismissed as absurd by all who knew him: he was enthusiastically heterosexual. Having failed to make the grade as a concert pianist in Vienna, he was packed off to the Raj, where he worked as a traffic superintendent on the East India Railway. Thoroughly bored, he met and married a Swiss-German beauty, a relationship that soon ended in acrimonious divorce.

Back in England, Strachey mixed effortlessly with the Bloomsbury Set, that decadent anti-establishment group who left a major imprint on twentieth-century culture. The writers Virginia and Leonard Woolf and the artists Duncan Grant, Roger Fry and Vanessa Bell would become lifelong friends. Fancy-dress parties were a regular fixture: at one, Strachey was the Harlequin; at another he came as the ballet dancer Nijinsky, dressed all in red. During long weekends in the country, he would spend hours debating ethics with the moral philosopher G. E. Moore, performing music, and playing marathon games of chess and bridge, two of his favourite pastimes.

Around this time, he met the genius codebreaker Dilly Knox, who was then deciphering ancient Greek poetry. Lytton Strachey, Oliver’s brother, was a contemporary of Dilly’s at Cambridge and developed a huge crush on him, which was not reciprocated. Oliver would bump into Dilly at Bloomsbury gatherings, and over the course of their long codebreaking careers they became firm friends.

In 1911, Strachey married Ray Costelloe. Known for her unflattering dress sense – her grandmother observed that ‘Ray sniffs at the idea of trying to make her look graceful … a hopeless task … but she has consented to give up those awful knickers for the summer’ – she was distinctly unfeminine and loved sport and fast cars. She read mathematics at Newnham College, Cambridge, and after graduating met Pippa Strachey, who was deeply committed to the women’s movement and worked for the Central Society for Women’s Suffrage. Ray joined and threw herself into organisational duties and campaigning. She would play a pivotal role in mobilising Britain’s women during the war.

After honeymooning in India, the newly-weds returned to London in early 1912. They moved into a tiny flat and lived off an allowance from Ray’s stepfather. The opportunity for Strachey to join MI1(b) came through a family friend at the War Office, who was ‘looking for someone with an ingenious head for puzzles and acrostics to decipher code and piece together scraps of wireless messages’. A meeting was arranged and he was hired on the spot. With his agile brain, his knowledge of languages, mathematics and music, his skill at games and puzzles, coupled with his love of detective novels that tested his ability to find clues and solve the mystery, he fitted in perfectly.

When Malcolm Hay arrived at MI1(b) in late summer 1915, work on Western Front material had slowed to a trickle: the Germans had for the time being stopped using wireless and were sending their messages via trench telephone. Instead, Strachey and his two compatriots were attempting ‘the reconstruction of the American diplomatic code books’. Without economic and financial support from America the Allies could not continue fighting. Knowing the intimate details of US policy could make all the difference between winning and losing. Hay immediately set about examining communications between James Gerard, the US ambassador in Berlin, and his government in Washington. According to Alice Ivy Hay, his second wife, Malcolm detected their meaning over the course of one night.

Without a steady stream of wireless intercepts to work with, Hay next turned his attention to the voluminous telegraph traffic passing through London. He discovered that copies of all foreign telegrams were kept by the cable censor, Lord Arthur Browne, who was a member of the War Office staff. It was thus possible to obtain copies of all the diplomatic cables which passed through London.

Up to this point, the idea that the confidential communications of neutral and friendly powers constituted fair game was anathema to the British establishment. Such behaviour was considered ungentlemanly, not worthy of an Englishman. Collecting them was one thing, reading them quite a different matter. Hay, however, was not bothered by etiquette. There was a war to win. He quickly realised the potential value of the enormous mass of encoded messages from all over the world which were accumulating in War Office cupboards. He met with Browne, who agreed to have all diplomatic cable traffic handed over to MI1(b).

Hay was also determined to rejuvenate MI1(b)’s relationship with Room 40. During the early months of the war, as both organisations were finding their feet, they worked in relative harmony. Alastair Denniston, one of Room 40’s first recruits, remembered how work on the ciphers continued in the Admiralty and the War Office by day, while the night watch worked in the War Office. However, this cordial
esprit de corps
soon broke down, as the long-held rivalry between the Admiralty and the War Office reasserted itself. As a result, ‘a definite breach’ occurred, and from then on the two sets of codebreakers worked in isolation.

Hay immediately recognised the need for them to cooperate and informally approached Blinker Hall. Never one to let institutional loyalty interfere with beating the Germans, Hall was happy to oblige, especially as Room 40 had also begun to deal with the Germans’ diplomatic communications, thanks to a bizarre chain of events in the Middle East.

When the Ottoman Empire entered the war in 1914, it brought with it hundreds of thousands of Muslims, the holiest sites in Islam and the supreme leader of the faith, the Sultan-Caliph Mehmed Rashad V. The Germans sensed an opportunity to destabilise the British Empire by appealing to its millions of Muslim subjects in India, North Africa and the Far East and rallying them to their standard.

A major step in that direction was taken when the Sultan-Caliph declared a jihad against the British in November 1914. An intensive propaganda campaign was launched by German agents, underground networks were established in Egypt, and a small, dedicated team was dispatched to foment uprisings in Persia (Iran), notionally independent but jointly controlled by Britain and Russia, and Afghanistan.

One of these insurrectionists was Wilhelm Wassmuss. The nearest German equivalent to Lawrence of Arabia, Wassmuss was a career diplomat, fluent in Persian and Arabic, who adopted the lifestyle of the desert tribes. An advocate of guerrilla warfare, he was single-handedly responsible for leading the British a merry dance in southern Persia: stirring up locals, capturing several towns, blowing up oil pipelines and taking hostages. An irritant rather than a major threat, Wassmuss inadvertently gifted Room 40 the code books that would ultimately transform Allied fortunes.

By the spring of 1915, the British were hot on his heels, but Wassmuss always managed to keep one step ahead, twice escaping the somewhat lacklustre efforts of local pro-British officials to hold him prisoner. At this point, history and myth collide. According to one account of events, when Wassmuss eluded his captors he left behind a chest containing secret papers, amongst them two versions of the German diplomatic code book, numbered 89734 and 3512. The British seized the trunk and it made its way to the India Office in London (Persia was under the jurisdiction of the Raj). Alternatively, the British, annoyed that Wassmuss had got away, arrested the German consul in the Persian Gulf for collaborating with him. During a search of the consul’s office safe they came across the code books. Not appreciating their potential value, they sent them back to London.