D-Day. The Battle for Normandy

Street of British journalists called forward to accompany the invasion force might be noticed.
    Everyone in Britain knew that D-Day was imminent, and so did the Germans, but the enemy had to be prevented from knowing where and exactly when. Censorship had been imposed on the communications of foreign diplomats from 17 April, and movement in and out of the country strictly controlled. Fortunately, the British security service had captured all German agents in Britain. Most of them had been ‘turned’ to send back misleading information to their controllers. This ‘Double Cross’ system, supervised by the XX Committee, was designed to produce a great deal of confusing ‘noise’ as a key part of Plan Fortitude. Fortitude was the most ambitious deception in the history of warfare, a project even greater than the maskirovka then being prepared by the Red Army to conceal the true target of Operation Bagration, Stalin’s summer offensive to encircle and smash the Wehrmacht’s Army Group Centre in Belorussia.
    Plan Fortitude had several aspects. Fortitude North, with fake formations in Scotland based on a ‘Fourth British Army’, pretended to prepare an attack on Norway to keep German divisions there. Fortitude South, the main effort, set out to convince the Germans that any landings in Normandy were a large-scale diversion to draw German reserves away from the Pas-de-Calais. The real invasion was supposedly to come between Boulogne and the Somme estuary during the second half of July. A notional ‘1st US Army Group’ under General George S. Patton Jr, the commander the Germans feared the most, boasted eleven divisions in south-east England. Dummy aircraft and inflatable tanks, together with 250 fake landing ships, all contributed to the illusion. Invented formations, such as a 2nd British Airborne Division, had been created alongside some real ones. To increase the illusion, two fake corps headquarters also maintained a constant radio traffic.
    One of the most important double agents to work for British intelligence on Fortitude South was a Catalan, Juan Pujol, who had the codename ‘Garbo’. With his security service handler, he constructed a network of twenty-seven completely fabricated sub-agents and bombarded the German intelligence station in Madrid with information carefully prepared in London. Some 500 radio messages were sent in the months leading up to D-Day. These provided details which together gradually made up the mosaic which the Double Cross Committee was assembling to convince the Germans that the main attack was to come later in the Pas-de-Calais.
    Subsidiary deceptions to prevent the Germans moving troops to Normandy from other parts of France were also dreamed up. Plan Ironside conveyed the impression that two weeks after the first landings a second invasion would be launched on the west coast of France directly from the United States and the Azores. To keep the Germans guessing, and to prevent them moving the 11th Panzer-Division near Bordeaux north into Normandy, a controlled agent in Britain, known as ‘Bronx’, sent a coded message to her German controller in the Banco Espirito Santo in Lisbon: ‘ Envoyez vite cinquante livres. J’ai besoin pour mon dentiste .’ This indicated ‘that a landing would be made in the Bay of Biscay on about the 15th June’. The Luftwaffe, clearly fearful of a landing in Brittany, ordered the immediate destruction of four airfields close to the coast. Another diversion, Operation Copperhead, was mounted in late May when an actor resembling General Montgomery visited Gibraltar and Algiers to suggest an attack on the Mediterranean coast.
    Bletchley Park, the highly secret complex about fifty miles north-west of London which decoded enemy signals, adopted a new watch system for Overlord from 22 May. Its experts were ready to decrypt anything important the moment it came in. Thanks to these ‘Ultra’ intercepts, they were also able to check on the success of Fortitude disinformation provided by the main ‘Double Cross’ agents, Pujol, Dusko Popov (‘Tricycle’) and Roman Garby-Czerniawski. On 22 April, Bletchley had decoded a German signal which identified the ‘Fourth Army’, with its headquarters near Edinburgh and two component corps at Stirling and Dundee. Other messages showed that the Germans believed that the Lowland Division was being equipped for an attack on Norway.
    Ultra decrypts revealed in May that the Germans had carried out an