During May 1944, the Germans intensified their efforts to crush resistance activity in Europe. In France, a ‘Blood and Ashes’ campaign against Resistance fighters in the Auvergne led to the public hanging of ninety-nine of those caught. But as many as 35,000 active members of the French Resistance had now been identified, region by region, by British Intelligence, which sent them regular supplies of arms in preparation for a general uprising in support of the cross-Channel attack. In Yugoslavia, Tito’s partisans launched their own offensive that May, Operation Bearskin, to disrupt German road and rail communications northward through Slovenia, in an effort to make it more difficult for the Germans to move troops from the Balkans to France once the landings had begun.
In Britain on May 2, despite the disaster four days earlier at Slapton Sands, the last of the practice landings, Operation Fabius, was held at the same Assault Training Area, which included Slapton.
On May 2, in Germany, the journalist Erich Knauf, who had declared publicly not only that ‘a German victory would be the greatest misfortune’, but also that Himmler ‘only keeps his job by ordering between eighty and a hundred executions a day’, was himself executed. On the previous day, in London, a British court had sentenced to death a Belgian subject, Pierre Richard Neukermans, found guilty of having flown from Lisbon to Britain in order to spy against Britain; he was executed at the end of June.
The Allies continued to use the Germans’ own top-secret Ultra radio messages to improve their invasion plans. On May 3, a newly formed German division reached France; four days later, as a result of reading the German Army’s Ultra signals, the Anglo-American planners knew, not only of its existence, but of its strength—defensive only, and location—at the base of the Cotentin Peninsula.
Thus the most secret triumph of British Intelligence, and the hard, often laborious work of more than five thousand cryptographers and their helpers—work which four years earlier had been fraught with uncertainty and difficulty—reached a high point of decisive achievement, averting all danger of a ‘blind’ landing in France. One by one, every German military formation was precisely located.
On May 5, in a further success for their Intelligence services, the Germans were again able to eavesdrop on a telephone conversation between Churchill and Roosevelt. Something was in preparation, but what it was or where, or when, they could neither overhear nor deduce. Particularly galling for those who read the transcript of the discussion were Roosevelt’s final words: ‘Well, we will do our best—now I’ll go fishing.’
Allied ‘fishing’ was of a high order; also on May 5, as a result of clues received by Enigma, South African Air Force pilots flew a reconnaissance mission from Italy deep over southern Poland, to Blizyn, where they photographed a German flying bomb assembly and test centre. Both the rocket and its firing platform were identified by the Photographic Reconnaissance Unit at Medmenham, in Britain. To accelerate flying bomb production, on May 6 German rocket scientists, including Wernher von Braun, and senior SS officers, agreed that 1,800 skilled workers should be brought from France to work in the underground tunnels and facilities at Nordhausen; they were to be housed at the nearby Dora concentration camp, and treated as concentration camp inmates. Few of them were to survive the war.
On May 7, against Hitler’s wishes, General Schömer, commander of the South Ukraine Army Group, realizing that his forces could no longer hold the Crimean city of Sevastopol, ordered it to be evacuated by sea and air. More than thirty thousand soldiers were taken off before, on May 11, the last of the strongpoints was given up. But already, on May 10, the city was sufficiently in Soviet hands for Marshal Tolbukhin to report its capture to Stalin. That same day, in a somewhat disingenuous communiqué, the German High Command announced: ‘The ruins of Sevastopol were evacuated in the course of a disengaging move.’ Defeat had become disengagement.
In Western Europe, the planning and deception for Overlord were in their final month. On May 9, United States bombers struck at the principal German airfields in north-west Europe—Laon, Florennes, Thionville, St Dizier, Juvincourt, Orléans and Avord. That same day, in Stockholm, a deliberate British manipulation of the Swedish Stock Exchange, whereby Norwegian stocks rose by almost twenty per cent, was intended, as part of Operation Graffham, to give the impression that the liberation of Norway was near; that Norway, not France, was one of the destinations of the Allied forces being assembled in Britain.
Even the imminence of the landing was hidden from the Germans; on May 9, Admiral Dönitz told the Japanese Ambassador in Berlin, Count Oshima, that the Allies would not be able to invade ‘for some time’. Oshima’s radio report of this conversation, sent to Tokyo, was decrypted at Bletchley on May 13, providing welcome relief to the Anglo-American planners.
At eleven o’clock on the evening of May 11, in Italy, nearly two thousand Allied guns opened fire in a simultaneous artillery barrage from Cassino to the sea. Forty-five minutes later, the infantry began their attack—Indian, British, French, Polish and Moroccan troops among them. In this, the fourth battle for Cassino and its monastery, General Alexander had assembled a numerical superiority of three to one; but it was to take seven days before even this advantage could overcome the tenacious German defence. Meanwhile, on May 12, the United States Air Force launched a massive attack on German synthetic oil plants. The seven plants which were bombed that day produced together far more than a third of Germany’s total output of synthetic oil, on which the German forces were now almost entirely dependent for their capacity to continue at war.
Only eighty German fighters were available to meet this air onslaught by eight hundred bombers; since the beginning of the year, the Germans had lost more than three thousand fighter pilots either killed in action, or taken prisoner after their planes were shot down. Nevertheless, the German fighter pilots fought with skill and determination, shooting down forty-six bombers for the loss of thirty fighters. All seven targets were hit, three of them so seriously that they were temporarily shut down. The German’s own Ultra messages revealed to the Allies the extent of the German alarm.
Acts of sabotage were also accelerated as the cross-Channel invasion drew nearer; on May 13, at Bagnères-de-Bigorre, in the Pyrenees, a factory producing the carriers for self-propelled guns was put out of action for six months, after an attack by British agents and French Resistance fighters. That day, along the Channel coast, Rommel completed two formidable lines of underwater obstacles; altogether, 517,000 obstacles had been laid down in six feet of water for high tide and half tide, 31,000 of which were fitted with mines. But two further lines of obstacles, intended for six feet of water at low tide, and for twelve feet of water at low tide, were not yet in place.
On May 8, Rommel had warned the German High Command that the systematic Allied destruction of railways throughout northern France had begun to disrupt his supplies and troop movements; this most secret signal was decrypted in Britain on May 14. This was certainly an encouragement for the Americans to continue their attacks. The bombing of German airfields had also been effective, so much so that Goering ordered the Todt Organisation to carry out work at airfields which were no longer used, or hardly used, so as to deceive the Allies into diverting bomber resources against them. Unfortunately for Goering, his order, sent by a top-secret Ultra radio signal, was decrypted by British Intelligence on May 14, exposing the ruse.
The Germans were far more vulnerable to deception than the Allies; on May 15, the German High Command was informed that ‘A good Army Intelligence source’ had reported the presence of units of the First United States Army Group in Yorkshire and Norfolk. The ‘good’ source was in fact a former German agent who had long been working for Britain; the army group on which he was reporting so assiduously existed only in the minds of Britain’s deception planners. Yorkshire and Norfolk were the starting points for the fictitious attacks on Norway and the Pas de Calais.
On May 15, after two months of careful preparation, and amid massive and successful deception, the Germans began the deportation of hundreds of thousands of Jews from Hungary to Auschwitz. Four thousand were deported every day; on their arrival at Auschwitz, sometimes two-thirds, sometimes a half, would be gassed. Those who were not killed were sent to the barracks, to swell the ranks of slave labourers, including Polish, British, Yugoslav, French and Soviet prisoners-of-war, forced to work, and to suffer appallingly cruel privations, in the many factories set up specially around Auschwitz, or already in existence there.
Slave labour camps in Eastern Silesia, 1944
At the Upper Silesian industrial city of Gleiwitz, four factories received slave labourers from Auschwitz; one for the production and packing of black smoke for smoke screens, had been opened on May 3. The others were for repairing railway carriages and oil wagons, for making railway bogies and gun carriages, and for repairing and remodelling military motor vehicles.
In the East Upper Silesian power station and coal mine at Neu Dachs, known also by its Polish name, Jaworzno, more than sixteen hundred prisoners were employed by May 1944. At the synthetic-petrol plant at Blechhammer, opened on April 1, four thousand prisoners were employed. At Bobrek, from April 22, the two hundred and fifty prisoners employed by the Siemens Schuckert works included fifty children: all were employed making electrical apparatus for aircraft and submarines.
A further labour camp at Myslowice provided thirteen hundred slave labourers for the Fürstengrube coalmines, working the old mine and constructing a new one. Another thousand prisoners were employed at the Laurahütte steel works, making anti-aircraft guns. At the Günthergrube coalmines there were six hundred prisoners, most of them Jews brought from Auschwitz, working the old mine and constructing a new one. In May 1944, with the start of the mass deportation of Hungarian Jews, a new labour camp was opened at Sosnowiec, the second there, in which nine hundred prisoners worked at the gun-barrel foundry and in shell production.
Between the barracks and gas chambers at Birkenau, and Auschwitz Main Camp, fuses for grenades were manufactured at the Union factory. Several thousand Jewish women prisoners were employed there. At Monowitz, the vast Buna synthetic oil and rubber factory was already absorbing tens of thousands of Jewish workers, as well as some British prisoners-of-war, all non-Jews. Hungarian Jews were also to be sent from Auschwitz to the labour camp on the site of the Warsaw ghetto, to clear the rubble, and to search for valuables.
It was not only in the Auschwitz region that slave labour was being used for the German war effort. On May 15, the day of the first deportation of Hungarian Jews, a thousand Jews already at Auschwitz were sent to a factory at Wüstegiersdorf; others were to go to factories at Brünnlitz, Schwarzheide and Hamburg, as well as to a building site at Ullersdorf, south-east of Berlin, which was even then under construction as an SS recreation and rest centre.
It was on that fateful May 15, as the wheels of death began to roll from a thousand Hungarian towns and villages towards Auschwitz, that a Palestinian Jew, Enzo Sereni, who had been born in Italy, was parachuted by British Intelligence into the German-occupied half of the Italian peninsula. His mission was to contact Italian partisan groups near Florence, collect maps and military information for the eventual Allied advance into Tuscany, and help British prisoners-of-war who had escaped captivity. Immediately on landing, Sereni was captured; after four days of interrogation and torture at Verona, he was sent to a prison camp at Gries, then on to Dachau. There, six months after his capture, he was summoned from his barracks, and was never seen again.
From the Italian city of Fossoli, 575 Jews were deported to Auschwitz on May 16. When they reached Auschwitz seven days later, 518 were taken to their deaths, and only 57 to the barracks. Among those who were gassed immediately on their arrival was a baby girl, Gigliola Finzi, born at Roccastrada two and a half months earlier. Also gassed that day was Carolina Calo and her four small children, the youngest of whom, a boy, had been born on the first day of the seven day journey to death. Carolina Calo’s husband, Eugenio, a prominent Italian partisan leader, was even then capturing German soldiers in Tuscany, and preparing to take them southwards across the war zone to the Allied lines, before returning to German-occupied Italy to continue the fight behind the lines.
On the morning of May 18, after almost a week of continuous fighting, Polish troops raised their flag over the ruins of the monastery of Monte Cassino. The six month struggle to push beyond Cassino was over. In the final battle, 4,267 Allied troops were killed, and a further 4,068 ‘missing’: their bodies so pounded by shell fire that they were never found. On the following day, the Polish commander, General Wladyslaw Anders, visited the battlefield. ‘Corpses of German and Polish soldiers’, he wrote, ‘sometimes entangled in a deathly embrace, lay everywhere, and the air was full of the stench of rotting bodies.’ As Anders walked over the battlefield, he noted that ‘crater after crater pitted the sides of the hills, and scattered over them were fragments of uniforms and tin helmets, tommy guns, Spandaus, Schmeissers and hand grenades.’
That day, from Washington, came the announcement that in the most recent campaign for the successful capture of the Admiralty Islands, 326 American soldiers had been killed, and 3,820 Japanese. Only seventy-five Japanese had been taken prisoner, mostly those who were too gravely injured to be able either to fight to the death or to kill themselves rather than surrender. Two days later, on May 20, an American task force completed the conquest of Wadke Island, all eight hundred Japanese defenders having been killed for the loss of fifty-three American lives.
On May 20, a mere seventeen days before the Normandy landings, the Germans still did not know where those landings would be. The Germany Navy was even then mining the Bay of Biscay. When Rommel asked that it should start mining the Bay of the Seine, his request was refused. He was also refused troop dispositions which could cover Normandy and Brittany at the same time, a refusal that was due, he later wrote, ‘to fears of a possible enemy airborne landing in the neighbourhood of Paris’.
The Allied preparations now moved into high gear. On May 21, British and American aircraft launched Operation Chattanooga Choo-Choo, a systematic attack on railway engines and rolling stock throughout northern Europe, including Germany. So effective were these attacks that within twenty-four hours German municipalities were urgently seeking foreign slave labourers, and even Jews from concentration camps, to help repair the bomb damage.
For the Allies, secrecy remained the key to the possibility of success on the day of the Normandy landings—‘D-Day’ in military parlance. On May 23, at Sutton Coldfield, in Britain, an American officer in an Army Postal Unit who was privy to some of the Bigot secrets disclosed the objectives of the United States First Army to a member of the Adjutant General’s department who was not in the know. He was sentenced to confinement for one year, with hard labour, at the United States Disciplinary Barracks at Greenhaven, New York, to be followed by dismissal from the service.
The capture of Monte Cassino on May 18 had opened the way for a rapid Allied advance northwards, first to link up with the Anzio beachhead, and then to drive on to Rome. At Anzio, on May 23, more than 150,000 Allied soldiers broke out of the perimeter in which they had been trapped for four months. Along the coastline of those areas under German occupation, British and American patrol boats searched for escaped prisoners-of-war whom they could take off from danger and return to the Allied armies. On the night of May 24, in one such operation, ‘Darlington II’, two boats, setting off from Termoli to the mouth of the River Tenna, rescued a total of 153 escaped prisoners-of-war and airmen who had managed to avoid capture altogether after having been shot down; by the end of November, 2,156 escapees had been recovered by such means.
Behind the lines in Greece, German forces were being increasingly harassed by Greek guerrillas. On May 24 the entire population of the village of Pogonion was deported to a camp near Yanina, to be held as hostages. When, shortly afterwards, a German division was attacked by guerrillas, all 325 hostages were shot. In German-occupied Yugoslavia, May 25 saw the launching of Operation Knight’s Move, an attempt, by use of parachute and glider-borne troops, to seize the partisan leader, Tito, while he was at the village of Drvar. As the German troops moved in, one partisan, shot through the head, died in agony at Tito’s feet. Tito escaped; but the villagers in whose midst he had been living were almost all killed, women and small children as well as men.
In Italy, on May 25, the troops who had broken out at Anzio linked up with the advancing Allied forces. That day, American troops entered Velletri, less than twenty-five miles from the centre of Rome. In German-occupied Greece, a young Intelligence officer, Kurt Waldheim, was writing to his superior, General Schmidt-Richberg, with criticism of the most recent sweeps against the guerrilla bands, and the reprisals that accompanied them. ‘The reprisal measures imposed in response to sabotage and ambush’, he wrote, ‘have, despite their severity, failed to achieve any noteworthy success, since our own measures have been only transitory, so that the punished communities or territories soon have to be abandoned once more to the bands. On the contrary’—Waldheim added—‘exaggerated reprisal measures undertaken without a more precise examination of the objective situation have only caused embitterment and have been useful to the bands. It can be demonstrated that the population broadly supports the bands and supplies them with excellent information’.
From each German report, one can see the extent of the terror, and of resistance. On the same day that Lieutenant Waldheim was sending this report from Greece, SS Brigadier-General Edmund Veesenmayer was reporting to the German Foreign Office in Berlin that 138,870 Jews had been deported to their ‘destination’ in the past ten days. That destination was Auschwitz. At Auschwitz itself, on the evening of Veesenmayer’s report, as several hundred Hungarian Jews were being led to one of the two more distant gas-chamber buildings in Birkenau, they sensed that something was wrong, and scattered into the nearby woods. Special searchlights, installed around the gas chamber, were at once switched on by the SS, who opened fire on those seeking to flee. All were shot. A similar act of revolt, similarly suppressed, took place three days later.
‘Hungary!’ Hitler exhorted his generals at Obersalzberg on May 26. ‘The entire country subverted and rotten, Jews everywhere, Jews and still more Jews right up to the highest level, and the whole country covered by a continuous network of agents and spies waiting for the moment to strike, but fearing to do so in case a premature move drew us in. Here too I intervened, and this problem is now going to be solved too’.
As the Germans were more and more pressed back in the war zones, so, in Hungary and in other regions of central Europe—in Italy, Holland, France and Greece—Hitler and his subordinates hastened to ‘solve’ the Jewish question, by deporting every Jew they could find to Auschwitz, several thousand every day. At the same time, the western Allies, while on the verge of a cross-Channel invasion of northern Europe, were almost at the gates of Rome and were bombing German industrial centres and war factories without respite. As the outcome of the war became more starkly apparent, it was as if two victories were on offer; for Germany a victory over the Jews, and for the Allies a victory over Germany. There could no longer be victory for Germany, that was clear. Even Goebbels had declared, in a newspaper editorial on May 24: ‘Germany must be made more desolate than the Sahara.’ Nothing must be left which the Allies—and in particular the dreaded ‘Bolsheviks’—could plunder.
On May 25, British Intelligence decrypted a top secret message from Rommel, sent six days earlier to Berlin, in which he revealed that one SS panzer division had no tanks, and was not expecting any; it was seriously short of officers, motor transport and vehicle spares. Its transport included horses and bicycles. A further decrypt, of a German Air Force Enigma message, showed that it was expected that it was in the region of Dieppe that, in the German view, the landing would most probably come. It was the continual bombing attacks on the bridges over the River Seine which had led to this conclusion.
On May 26, in a daylight air raid on Lyon, intended to block the German reinforcement routes from the South, railway lines, power stations and military installations were massively bombed, and 717 French civilians killed.
Despite a protest by the regional Resistance leader, Alban Vistel, that the local population were ‘painfully indignant’, resistance continued; on the day after the Lyon bombing, in an ambush set by the Maquis, twelve members of the collaborationist Milice were killed. There were also many acts of sabotage. At Ambérieu, a railway engine depot was destroyed and fifty-two railway locomotives made unusable. At Bar, in the Corrèze, a hydro-electric station was so badly damaged on May 26 that it was put out of action for the next four months. That day, British Intelligence decrypted a message from Rommel, sent to Berlin sixteen days earlier, warning that the locomotive situation had become so serious that forced labour, and even prisoners-of-war, would have to be used at the repair shops; the French civilian work force was ‘not responding’.
Not only did the Ultra decrypts reveal to the Anglo-American planners the German Army’s weaknesses and problems in France, and the strength of individual units; they also showed precisely where those units were still being sent. A series of decrypts between May 24 and May 27 showed a sudden and considerable transfer of troops to the Cotentin peninsula, to the very area around La Haye-du-Puits where it was intended to drop American parachute troops, in order to protect the landing beaches from attack from the Cherbourg peninsula. On the evening of May 27, scarcely a week before the date originally set for the landings, the Americans had therefore to abandon the plan to drop men at La Haye-du-Puits; they had also to put back the date for the capture of Cherbourg itself by seven days. Ultra had saved the Allies from the potential disaster of landing men at a point strongly held by German troops.
On May 28, American bombers made their second raid on five of the German synthetic oil plants which they had already damaged on May 12. That night, British bombers attacked the reinforced concrete fortifications at St Martin de Varreville, overlooking the invasion beaches; a block house, command posts and signals equipment were destroyed. The air bombardment of railway marshalling yards had also continued, resulting not only in the disruption of German military movements by rail, but also in a total of three thousand French civilian deaths in forty-eight hours. ‘Terrible things are being done’, Churchill wrote to Eden on May 28. On the following day, after reading the reports of the attacks during May 28, Churchill wrote again, to Air Chief Marshal Tedder, the Deputy Supreme Commander of the Allied Expeditionary Force: ‘You are piling up an awful load of hatred.’
Hatred or not, the bombing was effective. On May 28, the destruction of the German naval wireless station at Château Terlinden, near Bruges, made it much more difficult for German Intelligence to ‘hear’ the extra volume of Allied wireless traffic, which would indicate the imminence of an Anglo-American land, air and sea assault.
The German air force, once so boastful under Goering, and capable of sustained and devastating bomber attacks, no longer had the resources both to bomb Britain and to prepare for the inevitable air battles of a cross-Channel attack. For their part, the Allies had continued with Operation Crossbow, attacking the flying bomb ‘Ski’ sites from the Pas de Calais to Dieppe. By the end of May, these sites were protected by 520 heavy guns and a further 730 guns of lighter calibre. In the Crossbow attacks, 154 Allied aircraft had been shot down by the end of May, with 771 aircrew dead or missing. But as many as two thirds of the ‘Ski’ sites had been put out of action.
An Allied air raid over northern France on May 31 was effective in another way; by cutting the German Air Force overland telephone cable at a point between Paris and Rouen, it interrupted telephonic communication between German headquarters in Paris and Air Force bases around both Rennes and Caen for three crucial days.
On May 31, a South African Air Force reconnaissance plane made its first flight over Auschwitz since the beginning of April, to photograph once more the German synthetic-oil plant at Monowitz. Two of the frames of its photographic cover showed, for the first time, not only the main camp at Auschwitz, but also the gas chambers, crematoria and extensive barracks of the Birkenau section, where tens of thousands of Jews were being held, and more than a million and a half Jews had already been killed. But the barracks and installations at Birkenau were not examined by the Photographic Reconnaissance Unit in Britain, whose only task was to identify, in as much detail as possible, the oil production process at Monowitz, with a view to bombing it. At Auschwitz, on the day of this reconnaissance flight, the SS camp administration recorded that a total of forty kilogrammes of gold had been taken from the teeth of the corpses of Hungarian Jews, who had been gassed in the fifteen days between May 17 and the end of the month. This included those gassed on May 31 itself, from two trains, out of which a thousand men and a thousand women had been sent to the barracks, and more than six thousand gassed, among them the two thousand Jews deported from the Hungarian city of Baja; during their three and a half day journey in sealed wagons, without food or water beyond that which they had managed to take with them, fifty-five had died, and two hundred had gone mad.
On June 1, the Anglo-American planners of the Normandy landings, now set for June 4, were shown the decrypt of a telegram from the Japanese Ambassador in Berlin, Count Oshima, to Tokyo. In it, Oshima reported on a conversation which he had had with Hitler four days earlier, when Hitler told Oshima that the Allies had completed their preparations; that they had assembled eighty divisions, eight of which had combat experience and were ‘very good troops’; that after diversionary operations in Norway, Denmark, south-west France and on the French Mediterranean coast, they would establish a bridgehead in Normandy or Brittany; and that after seeing how things went, they would embark on establishing a real second front in the Dover Strait.
Several things were clear from Hitler’s conversation; that while the Germans regarded an invasion either in Normandy or Brittany as definite, they did not know which it would be, nor did they regard it as imminent; several diversionary operations elsewhere were expected to come first. Also, it was believed in Berlin that the Pas de Calais would be the true focus of the main assault on Fortress Europe.
On the night of June 2 British bombers again bombed the French railway marshalling yards at Trappes. This raid marked the culmination of the ‘Transportation’ Plan, begun on March 6, whereby more than eight thousand British bombers had dropped forty-two thousand tons of bombs on railway marshalling yards in France and Belgium. American bombers had dropped a further eleven thousand tons of bombs in May alone. June 2 also saw the first of a new series of bombing operations over central Europe, when American bombers, flying from Foggia and other airbases in southern Italy, struck deep into the industrial regions of Silesia, Hungary and Roumania, and then flew on to Soviet airbases in and around Poltava. By flying straight on to Poltava, the bombers did not have to face a return flight which their fuel consumption would have made impossible.
Devised to help the Red Army during its Roumanian offensive, as a result of an urgent appeal from Stalin, these flights were given the code-name Operation Frantic Joe. To avoid offending Stalin, this was quickly modified to Operation Frantic. On the first run, the railway marshalling yards at Debrecen were hit on the way out, and the airfield at Focsani on the return flight.
On June 2, the Normandy landings were fixed for June 5. But bad weather seemed to make a postponement inevitable. In a most secret radio signal to Berlin, Field Marshal von Rundstedt had stated that the Allies would need four consecutive days of good weather in order to carry out a cross-Channel assault. No such four day clear period was forecast. He, Rundstedt, was therefore certain that the invasion could not take place in the first week of June.
The secret communications code which von Rundstedt had used for his message about the weather was in a cypher which the British had broken. His message was therefore decrypted at Bletchley, where more than six thousand people were now employed, and passed on immediately to Eisenhower. From that moment, as a result of reading not only the message but the mind of his opposite number, Eisenhower knew that if he could launch the invasion in conditions ruled out by von Rundstedt, he would catch the Germans unawares.
The weather over the Channel, bad on June 2, began to deteriorate in the early afternoon of June 3. The German forecasters predicted bad weather for the next three or four days. This ruled out June 5 or June 6 as days on which an assault would be launched. Increased Allied wireless traffic might have caused this confident assumption to be reviewed, but on June 3 the German wireless intercept station on the Cherbourg peninsula, at Urville-Hague, was destroyed by air attack. Ironically, it had not been identified as an intercept station, but only as an ‘important installation of a special character’. That was enough, however, for it to become a target. Thus the two chief intercept stations covering the landing area—Château Terlinden and Urville-Hague—were out of action.
Eisenhower knew that the bad weather made it impossible to go ahead on June 5. But both the juxtaposition of the moon positions, plus the knowledge that the Germans expected no assault anywhere for the next three to four days, made it desirable that too great a delay beyond June 5 should be avoided.
On the morning of June 4, there was a forecast of a brief spell of better weather. But it was not the four clear days which the Germans regarded as the Allied minimum; it was therefore unlikely that the Germans would be alerted or alarmed. Thanks to knowledge provided by Ultra, the risks to the Allies of launching the invasion under the poor prevailing weather conditions would be more than compensated for.
On the evening of June 4, American troops reached the centre of Rome. ‘How magnificently your troops have fought!’ Churchill telegraphed that day to Roosevelt. On the following day, after a formal and triumphal entry into the Italian capital, the Allied troops continued their northward pursuit of the retreating Germans. But for those in charge of the Allied fortunes, the thrill of the fall of the first Axis capital to Allied arms was offset by the knowledge that on the morning of June 6, the largest amphibious operation of all time was to be launched, and the lives of hundreds of thousands of men put at risk. ‘I feel so much for you’, Churchill’s wife Clementine wrote to her husband on June 5, ‘at this agonizing moment—so full of suspense, which prevents one from rejoicing over Rome!’
Waking on the morning of June 5, Eisenhower knew that within twenty-four hours the die would already have been cast. That same morning, confident that the continuing bad weather meant that no invasion was imminent, Rommel left his headquarters at La Roche Guyon, by car, on his way to Germany, where he intended to speak to Hitler personally, and to impress upon him ‘the extent of the man-power and material inferiority we would suffer in the event of a landing’, and to request the despatch to northern France of two further panzer divisions, an anti-aircraft corps, and other reinforcements.
It was the bad weather on June 5 which kept almost all the German Air Force reconnaissance aircraft grounded. Five reconnaissance sorties were flown, but none reported any unusual activity in the ports of southern England. At 9.30 that evening a coded British wireless message, sent openly on the BBC, instructed French Resistance operatives to cut railway lines throughout France. German Intelligence, which had partially broken the code, warned Rommel’s headquarters at La Roche Guyon; but in Rommel’s absence no notice seems to have been taken of the warning. Of 1,050 planned breaches of the railway lines, 950 were carried out.
A message sent by the German Air Force High Command shortly before midnight on June 5, showed the extent of German weakness in the air as a result of the growing shortage of fuel oil. The message was an instruction to the First Parachute Army, based at Nancy, to conserve its consumption of aircraft fuel as much as possible. ‘With reduction of aircraft fuel by Allied action,’ the message read, ‘most essential requirements for training and carrying out production plans can scarcely be covered by quantities of aircraft fuel available.’ Wherever possible, the High Command added, the supply of goods to air units, and ‘duty journeys in general’, must be made by rail.
On the night of June 5, more than a thousand British bombers struck at the ten most important German gun batteries in the assault area, dropping five thousand tons of bombs. That same night, more than three thousand ships—British, American, Polish, Dutch, Norwegian, French and Greek—Operation Neptune—were crossing the Channel. As this vast armada drew closer and closer to the Normandy beaches, a series of deceptions was launched on other possible destinations; the largest of all, Operation Taxable, involved the dropping of dummy parachutists near Boulogne, and the dropping of a vast number of radar-jamming strips in such a way as to produce on German radar screens the appearance of a large, slow-moving convoy edging its way across the Channel towards the Pas de Calais. A further spurious raid, using motor launches and electronic deception to simulate the movement of a large convoy, was made towards the beaches between Le Havre and Dieppe. A third deception that night, by motor launches off Harfleur, was designed to suggest a similar threat east of Le Havre. So successful was one particular dummy parachute drop, Operation Titanic, at Marigny, that, as its planners intended, it drew a whole German infantry regiment from its position in reserve at Bayeux, a mere six miles from the real landing beaches, as far west as the Carentan-Isigny area. Deception had played its part to the end, Ultra having revealed in detail just who needed to be deceived, now revealed that the deception had been successful.
At 11.55 on the evening of June 5, British infantrymen, members of the 6th Airborne Division, landed by gliders at the village of Bénouville, six miles north of Caen. Operation Overlord had begun.