... decrypt was from Hitler to Field Marshal Rommel. The invasion of Normandy was ... machines working around the clock at Bletchley Park. With the arrival of peacetime Churchill ordered that eight of these be destroyed, along with the Bombes ... A journey along one of Britain's oldest roads, from Dover to Anglesey, in search of the hidden history that makes us who we are today. 'A bravura piece of writing - Bill Bryson on acid' Tom Holland Winding its way from the White Cliffs of Dover to the Druid groves of Anglesey, the ancient road of Watling Street has gone by many different names. It is a road of witches and ghosts, of queens and highwaymen, of history and myth, of Bletchley Park codebreakers, Chaucer, Boudicca, Dickens and James Bond. But Watling Street is not just the story of a route across our island. It is an acutely observed exploration of Britain and who we are today, told with wit and an unerring eye for the curious and surprising.

... Machines, for use at Bletchley Park. The key to Bletchley Park's success in decoding German communications lay in ... Churchill, ordered most of the machines destroyed at the end of the war. Thinking Machines In 1945, John von ... In this new edition of the top-selling coursebook, seasoned historians Peter J. Bowler and Iwan Rhys Morus expand on their authoritative survey of how the development of science has shaped our world. Exploring both the history of science and its influence on modern thought, the authors chronicle the major developments in scientific thinking, from the revolutionary ideas of the seventeenth century to contemporary issues in genetics, physics, and more. Thoroughly revised and expanded, the second edition draws on the latest research and scholarship. It also contains two entirely new chapters: one that explores the impact of computing on the development of science, and another that shows how the West used science and technology as tools for geopolitical expansion. Designed for entry-level coll

Turing’s Enigma-cracking ‘bombe’ was one of his major contributions to winning the war. His revolutionary machine gave the Allies open access to Germany’s secret military communications. This chapter explains what the bombe was for and how it worked. Jean Valentine and Catherine Caughey, both Bletchley Park ‘Wrens’, describe their first encounters with Turing’s awe-inspiring bombes. They speak of the morale-sapping secrecy that surrounded the work of bombe operators. Jean Valentine also describes a visit to the secret factory where the bombes were made. Poland’s codebreakers were reading German military Enigma from early 1933. Their intellectual leader was the legendary Marian Rejewski, one of the twentieth century’s greatest codebreakers. As explained in Chapter 11, Rejewski and his colleagues invited a party of their British opposite numbers to Poland a few weeks before Hitler’s army poured across the frontier. An ultrasecret meeting took place at the Biuro Szyfrów (the cipher bureau), a cluster of buildings hidden in the forest at Pyry, near Warsaw. The visitors included Dilly Knox, at that time Britain’s most experienced warrior against Enigma (see Chapter 11), and Commander Alastair Denniston, head of British military and civil codebreaking. ‘The Poles called for us at 7 a.m.’, recalled Denniston, ‘and we were driven out to a clearing in a forest about 20 kilometres from Warsaw’. The Poles had decided to reveal everything before it was too late. ‘At that meeting we told everything we knew and showed everything we had’, Rejewski said. After the meeting, Knox sang for joy—although his immediate reaction, as he had sat listening to Rejewski’s codebreaking triumphs, had been undisguised fury that the Poles were so far ahead of him. In 1938 Rejewski and his colleagues had built a small machine they called a ‘bomba’. Their reasons for choosing this distinctive name, whose literal meaning is ‘bomb’ or ‘bombshell’, went unrecorded at the time, and theories later abounded. At Bletchley Park Turing told Joan Clarke, to whom he was briefly engaged, that the bomba ‘got this nickname because it made a ticking noise, like an anarchist’s time bomb’ (as she recollected).

This chapter summarizes Turing’s principal achievements at Bletchley Park and assesses his impact on the course of the Second World War. On the first day of the war, at the beginning of September 1939, Turing took up residence at Bletchley Park, the ugly Victorian mansion in Buckinghamshire that served as the wartime HQ of Britain’s military codebreakers (Fig. 9.1). There Turing was a key player in the battle to decrypt the coded messages generated by Enigma, the German forces’ typewriter-like cipher machine. Germany’s army, air force, and navy transmitted many thousands of coded messages each day during the Second World War. These ranged from top-level signals, such as detailed situation reports prepared by generals at the battlefronts and orders signed by Hitler himself, down to the important minutiae of war such as weather reports and inventories of the contents of supply ships. Thanks to Turing and his fellow codebreakers, much of this information ended up in Allied hands—sometimes within an hour or two of its being transmitted. The faster the messages could be broken, the fresher the intelligence that they contained, and on at least one occasion the English translation of an intercepted Enigma message was being read at the British Admiralty less than 15 minutes after the Germans had transmitted it. Turing pitted machine against machine. Building on pre-war work by the legendary Polish codebreaker Marian Rejewski, Turing invented the Enigma-cracking ‘bombes’ that quickly turned Bletchley Park from a country house accommodating a small group of thirty or so codebreakers into a vast codebreaking factory. There were approximately 200 bombes at Bletchley Park and its surrounding outstations by the end of the war. As early as 1943 Turing’s machines were cracking a staggering total of 84,000 Enigma messages each month—two messages every minute. Chapter 12 describes the bombes and explains how they worked. Turing also undertook, single-handedly at first, a 20-month struggle to crack the especially secure form of Enigma used by the North Atlantic U-boats. With his group he first broke into the current messages transmitted between the submarines and their bases during June 1941, the very month when Winston Churchill’s advisors were warning him that the wholesale sinkings in the North Atlantic would soon tip Britain into defeat by starvation.