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June 1944 : The Beginning of the End

June 1944 marks the last opportunity the Germans have to stem the tide that is now carrying them to certain defeat. The fall of Rome, two days before D-day, shows that the Germans cannot expect to defeat the Allies in the field, now that they no longer have superiority in the air or at sea. Their only hope is to create a disaster for the Allies that will cause them to question whether it is desirable to prolong the costly fight. To defeat the landings in Europe, as they had at Dieppe, seems the last opportunity to attempt an honourable peace in the West so that they can concentrate on stemming the Russians. For the British, the landings on D-day are to be the high water mark, a triumph of organisation and the human spirit; their leaders know that from now on they will be unable to fully replace their losses and the US will inevitably soon become the senior partner as the US forces grow to dominance. The German population had been told that their secret weapons will redress the balance, but on D-day these are hardly in evidence, even if the oyster mines prove a major irritant. Then, six days later, comes the launching of the V-bomb offensive, too late to damage the invasion armada that had been a soft target, crammed into the south coast ports, but perhaps enough of a menace to London to divert the direction of the Allied offensive to deal with it? But impressive as the technology is, Allied bombing has reduced the scale of what had been intended to be a flood to a minor stream; serious enough for the war-weary inhabitants of London but not enough of a problem to make an impact on the land battle. And then, following the Russian offensive against Finland that opens on 11th June, the major Russian offensive starts on the 23rd June, within a week tearing open the whole centre of the long line. By the end of the month Cherbourg has fallen to the US forces, and all realistic hope of throwing the Allies back into the sea has gone. On 1st July von Rundstedt warns Keitel, Hitler’s Chief of Command; when the despairing Keitel cries out ‘What shall we do?’ von Rundstedt replies ‘Make peace, you fools’. The Germans will still fight hard, even sometimes brilliantly, but the end of the story is now inevitable.

Italy and the Entry into Rome. The entry into Rome on 4th June, two days before D-day, marks the success of the fourth Allied attempt to break the Gustav line and capture Monte Cassino. General Alexander, helped by his Chief-of-Staff General Harding, has personally taken control of the campaign, which involves a most successful deception operation. The Allies have made it known through double agents, etc, that they are planning to land far behind the German line in the Genoa- Leghorn area. The landing barges being assembled for the invasion of the south of France, now postponed until mid August, help this deception. Much of the Eighth Army is transferred to the left. The attack on 11th May achieves complete surprise, with Kesselring holding his reserves to repel the expected landings.

Displaying incredible bravery, the R.E.s bridge the Rapido under intense fire. The brilliant advance of the French colonial forces under General Juin outflanks Monte Cassino. By the 15th May the Gustav line is broken, though the German Paras still hold out fanatically on Monte Cassino. At last on the 18th the ruined Benedictine abbey taken over by the Polish Corps who suffer severe casualties in their two assaults. The Canadians are now leading the advance through the German defensive lines. On 23rd May the US 5th Army breaks out from the Anzio beachhead. General Alexander had ordered that the breakout should be eastwards to join up with the northwards advancing forces to cut off the German 10th Army. But General Mark Clark prefers the glory of capturing Rome and turns the breakout north-west. The Germans, facing the inevitable, declare Rome an open city, and though General Clark saw his entry into the city as valuable propaganda just before D-day, Churchill had already discounted this in writing to Alexander on the 28th May: ‘It seems much more important to cut their line of retreat than anything else. A cop is what matters. Boniface attributes to you only 700 serviceable tanks, CIGS furnishes me with figures showing you have at least 2,500 serviceable. Surely one half of these could be used to cut off the enemy’s retreat’. It is interesting to see Churchill studying the decrypts from BP - and still using the ‘spy’s’ name initially used to cover what had long become called Ultra. The Allies make steady progress advancing up Italy, breaking through the Caesar, Senger, & Albert lines and going on north to take Assisi and Perugia. But the advance is then to be halted as seven Allied divisions are taken out of the line to prepare for the futile landings in the south of France that the US declares must still be made. The British make use of the Ultra evidence that Hitler fears an Allied breakout into the Po valley, to try, to no avail, to persuade the US to cancel the landings in favour of continuing with the successful Italian campaign. During this whole summer in Italy much Intelligence is available with little delay. As well as copious Enigma breaks, the Bream Fish link from Berlin to Rome, (moved back to Florence), provides excellent information about the German order of battle, his strengths and tank serviceability returns. On 19th May Bream discloses Kesselring’s plans for the forces withdrawn from Cassino. Throughout June Fish and Enigma provide detailed information on his divisions, and on German reinforcements as they attempt to stem the Allied progress but are forced back steadily to the Gothic line. Hitler’s interventions with Kesselring, as he attempts to stop the German retreat are regularly decrypted. The ‘Flivos’ daily surveys of the battle from the Enigma Army-Air liaison key, Puma, prove particularly valuable. Army Y, principally derived from German, difficult to intercept, divisional VHF links, is a valuable source of tactical Intelligence, performing as well as it had ever done in Africa, with two of the German divisions transmitting the highest volume of traffic ever intercepted. Allied fighter-bombers prove particularly effective, as decrypts often disclose, operating by day and by night using parachute flares.

The D-day Landings. The Allies land in Normandy on the morning of 6th June from the largest sea-borne armada the world has ever seen, or is likely ever to see again. Some 3,000 vessels set out from ports on the south coast of Britain on the evening of 5th June, arriving off five landing beaches shortly after dawn, carrying a further 3,500 small landing craft that will soon be putting their human cargoes down on the sands. Eisenhower had had to take the difficult decision to delay the landings from the intended 5th June by bad weather, but it is then detected that a short window in the bad weather is going to arise on the 6th. At a meeting of his senior commanders together with his chief meteorologist, Group Capt. Stagg, Eisenhower takes the historic decision ‘O.K. We’ll go!’ By great good fortune, this brief break in the weather has not been spotted by the Germans. The bad weather forecast puts them off their guard, with Rommel, the local Commander, away in Germany for his wife’s birthday, several of the senior officers away on a course in Rennes, and most of the coastal forces keeping their heads down until the weather improves. This slows the reaction, even after they realise from the colossal bombardment that the landings are actually taking place. Though the area chosen for the landings comes as no surprise to Rommel and his senior as C-in-C West, von Rundstedt, as a result of the success of the deception programme both Rommel and von Rundstedt are convinced still larger ones in the Pas de Calais will follow these Normandy landings.

Once the coastal defenders recover from the preliminary air and sea bombardment, the landings are strongly opposed on all five beaches, except Utah where the US troops land with little opposition at least a mile south of the intended beach. But it is only on the other US beach, Omaha, that the opposition is so strong that success is in any serious doubt. The bombing has failed to destroy the fortifications overlooking this beach, and the swimming tanks are put into the water too far out so they sink in the rough seas. But even here, by mid-day the Americans are beginning to find ways off the deadly beach and are overwhelming the thin crust of the defences.

Canadian beach General Hobart’s ‘Funnies’, tanks fitted with a variety of devices for overcoming the beach defences that land with the first wave of troops, soon force a way off the beaches. The casualties on the beaches continue throughout the mornings from German long-range guns, and landing craft continue to be sunk by the beach obstacles as these become covered by the rising tide. But by evening some 130,000 troops are ashore together with some 23,000 airborne troops who first started landing on the two flanks of the invasion in the early hours of the morning from gliders and by parachute. So the landings may be considered as a great success, with Allied losses that day about 4,500, considerably less than the 20,000 that had been feared by Churchill. But once off the beaches, despite the bravery shown by individuals, the troops show the impact of the awful journey in the rough seas, and the terrible experience of the landings, especially for the many who have never been under fire; they are slow to move inland and except on the left flank, where the Paras seize the bridges over the Orne Canal and hold them even against enemy tanks, none of the D-day objectives is fully reached. This is particularly serious in the case of the British and Canadian failure to take the crucial communication centre of Caen, delayed by the 21st Panzer division though its counterattacks were thwarted by guns and anti-tank weapons; army Y had warned that it was going to attack in the evening.

D-day Intelligence. The aerial erected in Bletchley Park proves its worth on D-day when messages derived from decrypts are sent to the Naval Commanders and Signals Liaison Units, even as the armada is crossing the Channel. Some messages are dispatched from BP within 30 minutes of origination and interception by the Wrens in Hut 18! These warn that the Germans are reporting the parachute landings, tell of the sailing of the E-boats from Cherbourg, and disclose the instructions to the U-boats. The first message from the German Naval HQ in Normandy reporting at 0630 hrs that enemy tanks are ashore, is signalled from BP at 0910 hrs, following some 40 messages that have gone out from BP that morning. The Battle for Normandy: June. Rommel knows he must assemble a sizable force to mount a counter-attack in the days after D-day before the Allies have had time to sort themselves out and deploy their full strength. But each time he attempts to form a reserve he is forced to send the newly arriving Panzer forces piecemeal to plug a new hole that has appeared in the line. The belief that further landings are to come in the Pas de Calais ensures that substantial forces are held there throughout the month that might have made a significant difference in Normandy. The attempts by Montgomery on the left flank of the Allied line to by-pass and then take Caen by a pincer movement fail, but do have the inestimable advantage of drawing Rommel’s best forces to that flank, so helping the US to seal off the Cotentin Peninsula on 18th June and drive north for Cherbourg. In a major feat of arms General Collins and his VII Corps take Cherbourg on the 26th June but the port is so thoroughly demolished that it proves virtually unusable until mid September. However the Mulberry Harbours are proving just adequate, and even the loss of the one off the US beaches, in the great storm on 19th June, delays but does not seriously disrupt the build-up as the Americans prove masters at landing materiel across the open beaches. In the fighting in June it becomes apparent that both sides have some excellent divisions and a number of indifferent ones. The British have to relearn close cooperation between their ground forces and their air support. And their armoured forces have to learn the dangers of becoming exposed to the more experienced and better equipped Panzer forces. But the Allied overwhelming air dominance and ground firepower, not least from the long-range guns of the Battleships, is wearing the Germans down, causing huge casualties. By mid-July the Germans have lost 96,000 soldiers, only receiving 6,000 replacements, as well as losing 225 tanks. Rommel correctly predicts that the German front will collapse within a month.

For some weeks after D-day, out of an average daily intercept load of 4,840 signals, BP processes a daily average of 2,500 Army and Air Force decrypts obtained from about 30 Enigma keys, together with a smaller selection from the naval Enigma decrypts, of which the total rises from 1,500 to 2,000 daily over this period. But little Intelligence of direct value to the forces coming off Juno and Gold beaches is obtained from Ultra before 9th June. A few days before D-day Hut 6 had broken the local Flivos’ key, Ocelot; this key starts to produce valuable Intelligence from 8th June, such as about the counter-attacks planned by the Panzer divisions arriving at the fast solidifying front. Then, as the radio traffic mounts steeply after D-day, within a few days Hut 6 succeeds in breaking several German army Enigma keys in use in Normandy: Duck used by Rommel’s 7th Army; Pullet the Y service key; Penguin used by the 12th Panzer division which has moved from the Lisieux area to join the fighting west of Caen on 7th June; and Peewit, a Western front supply key. They also break a further six Luftwaffe keys during June, a truly remarkable achievement for Hut 6, since they are struggling to handle a heavier load of decrypts than they have ever read before. With the aid of these new sources, BP can now track the movement of the reinforcements as they move into the battle zone, and provide warning of counter-attacks. The US operations in the Cotentin were especially aided by frequent decrypts. Fish decrypts are made all the more difficult because soon after D-day the Germans start to change the code-wheel patterns every day on the all-important Jellyfish link to Paris. But the Mk II Colossus enters service on 1st June, the Dollis Hill team assembling the improved machine in Block F to save time. (It is reported that they had to work until 3.00 am to keep their promise).

The Bletchley Park Trust welcomes the preparation of these notes, but the authors are responsible for the statements and the views expressed.

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