These were soon to be further reinforced by two 13.5-inch guns from the old battleship Iron Duke, Iron Duke, which were being erected on railway mountings, and a battery of four 5.5-inch guns from H.M.S. which were being erected on railway mountings, and a battery of four 5.5-inch guns from H.M.S. Hood. Hood. Many of these additional guns were manned by the Royal Navy and Royal Marines. Many of these additional guns were manned by the Royal Navy and Royal Marines.

Although still inferior in numbers to the enemy we thus had a powerful fire concentration.

In addition one of the eighteen-inch howitzers I had saved after the First World War and twelve twelve-inch howitzers were installed for engaging enemy landings. All these were mobile and would have brought a terrible fire on any landing-area.

As the months of July and August pa.s.sed without any disaster, we settled ourselves down with increasing a.s.surance that we could make a long and hard fight. Our gains of strength were borne in upon us from day to day. The entire population laboured to the last limit of its strength, and felt rewarded when they fell asleep after their toil or vigil by a growing sense that we should have time and that we should win. All the beaches now bristled with defences of various kinds. The whole country was organised in defensive localities. The factories poured out their weapons. By the end of August we had over two hundred and fifty new tanks! The fruits of the American "Act of Faith" had been gathered. The whole trained professional British Army and its Territorial comrades drilled and exercised from morn till night, and longed to meet the foe. The Home Guard overtopped the million mark, and when rifles were lacking grasped l.u.s.tily the shotgun, the sporting rifle, the private pistol, or, when there was no firearm, the pike and the club. No Fifth Column existed in Britain, though a few spies were carefully rounded up and examined. What few Communists there were lay low. Everyone else gave all they had to give.

When Ribbentrop visited Rome in September, he said to Ciano: "The English Territorial defence is non-existent. A single German division will suffice to bring about a complete collapse." This merely shows his ignorance. I have often wondered, however, what would have happened if two hundred thousand German storm troops had actually established themselves ash.o.r.e. The ma.s.sacre would have been on both sides grim and great. There would have been neither mercy nor quarter. They would have used terror, and we were prepared to go all lengths. I intended to use the slogan, "You can always take one with you." I even calculated that the horrors of such a scene would in the last resort turn the scale in the United States. But none of these emotions was put to the proof. Far out on the grey waters of the North Sea and the Channel coursed and patrolled the faithful, eager flotillas peering through the night. High in the air soared the fighter pilots, or waited serene at a moment's notice around their excellent machines. This was a time when it was equally good to live or die.

14.

The Invasion Problem

Former Studies of Invasion - The New Air Power - My Statement to Parliament of June 18 - The First Rumours, June 27, 1940 - My Note of June 28 - My Note on "Invasion" of July 10 - Importance of Mobile Reserves - Two Thousand Miles of British Coastline - The First Sea Lord's Memorandum - Distribution of Potential Attack - I Double His Estimate for Safety - My Minute of August 5, 1940 - My Suggested Distribution of Our Army - Coincidence of Chiefs of Staff View - Our Emphasis on East Coast - The Germans Choose the South Coast - We Turn Our Front - Change in Our Dispositions Between August and September - Persisting Dangers from Across the North Sea - Tension in July and August.

AFTER D DUNKIRK, and still more when three weeks later the French Government capitulated, the questions whether Hitler would, or secondly could, invade and conquer our island rose, as we have seen, in all British minds. I was no novice at this problem. As First Lord I had for three years before the First Great War taken part in all the discussions of the Committee of Imperial Defence upon the point. On behalf of the Admiralty I had always argued that at least two divisions out of our Expeditionary Force of six should be kept at home until the Territorial Army and other wartime forces became militarily effective. As Admiral "Tug" Wilson put it, "The Navy cannot play international football without a goal-keeper." However, when at the outbreak of that war we found ourselves with the Navy fully mobilised, the Grand Fleet safe beyond hostile ken at sea, all surprises, treacheries, and accidents left behind us, we felt ourselves able at the Admiralty to be better than our word. At the extraordinary meeting of Ministers and high military authorities which Mr. Asquith summoned to the Cabinet Room on August 5, 1914, I declared formally, with the full agreement of the First Sea Lord (Prince Louis of Battenberg), that the Navy would guarantee the protection of the island against invasion or serious raid even if all the Regular troops were immediately sent to the great battle impending in France. So far as we were concerned, the whole Army could go. In the course of the first six weeks all the six divisions went.

Sea-power, when properly understood, is a wonderful thing. The pa.s.sage of an army across salt water in the face of superior fleets and flotillas is an almost impossible feat. Steam had added enormously to the power of the Navy to defend Great Britain. In Napoleon's day the same wind which would carry his flat-bottomed boats across the Channel from Boulogne would drive away our blockading squadrons. But everything that had happened since then had magnified the power of the superior navy to destroy the invaders in transit. Every complication which modern apparatus had added to armies made their voyage more c.u.mbrous and perilous, and the difficulties of their maintenance when landed probably insuperable. At that former crisis in our island fortunes we possessed superior and, as it proved, ample sea-power. The enemy was unable to gain a major sea battle against us. He could not face our cruiser forces. In flotillas and light craft we outnumbered him tenfold. Against this must be set the incalculable chances of weather, particularly fog. But even if this were adverse and a descent were effected at one or more points, the problem of maintaining a hostile line of communication and of nourishing any lodgments remained unsolved. Such was the position in the First Great War.

But now there was the air. What effect had this sovereign development produced upon the invasion problem? Evidently if the enemy could dominate the narrow seas, on both sides of the Straits of Dover, by superior air power, the losses of our flotillas would be very heavy and might eventually be fatal. No one would wish, except on a supreme occasion, to bring heavy battleships or large cruisers into waters commanded by the German bombers. We did not in fact station any capital ships south of the Forth or east of Plymouth. But from Harwich, the Nore, Dover, Portsmouth, and Portland we maintained a tireless, vigilant patrol of light fighting vessels which steadily increased in number. By September they exceeded eight hundred, which only a hostile air power could destroy, and then only by degrees.

But who had the power in the air? In the Battle of France we had fought the Germans at two and three to one and inflicted losses in similar proportion. Over Dunkirk, where we had to maintain continuous patrol to cover the escape of the Army, we had fought at four or five to one with success and profit. Over our own waters and exposed coasts and counties Air Chief Marshal Dowding contemplated profitable fighting at seven or eight to one. The strength of the German Air Force at this time, taken as a whole, so far as we knew and we were well informed apart from particular concentrations, was about three to one. Although these were heavy odds at which to fight the brave and efficient German foe, I rested upon the conclusion that in our own air, over our own country and its waters, we could beat the German Air Force. And if this were true, our naval power would continue to rule the seas and oceans, and would destroy all enemies who set their course towards us.

There was, of course, a third potential factor. Had the Germans with their renowned thoroughness and foresight secretly prepared a vast armada of special landing craft, which needed no harbours or quays, but could land tanks, cannon, and motor-vehicles anywhere on the beaches, and which thereafter could supply the landed troops? As had been shown, such ideas had risen in my mind long ago in 1917, and were now being actually developed as the result of my directions. We had, however, no reason to believe that anything of this kind existed in Germany, though it is always best when counting the cost not to exclude the worst. It took us four years of intense effort and experiment and immense material aid from the United States to provide such equipment on a scale equal to the Normandy landing. Much less would have sufficed the Germans at this moment. But they had only a few Siebel ferries.

Thus the invasion of England in the summer and autumn of 1940 required from Germany local naval superiority and air superiority and immense special fleets and landing craft. But it was we who had the naval superiority; it was we who conquered the mastery in the air; and finally we believed, as we now know rightly, that they had not built or conceived any special craft. These were the foundations of my thought about invasion in 1940, from which I gave from day to day the instructions and directives which these chapters contain.

I laid the broad outlines plainly before Parliament on June 18: The Navy has never pretended to be able to prevent raids by bodies of five or ten thousand men flung suddenly across and thrown ash.o.r.e at several points on the coast some dark night or foggy morning. The efficacy of sea-power, especially under modern conditions, depends upon the invading force being of large size. It has to be of large size, in view of our military strength, to be of any use. If it is of large size, then the Navy have something they can find and meet and, as it were, bite on. Now we must remember that even five divisions, however lightly equipped, would require two hundred to two hundred and fifty ships, and with modern air reconnaissance and photography it would not be easy to collect such an armada, marshal it, and conduct it across the sea with any powerful naval forces to escort it; and there would be very great possibilities, to put it mildly, that this armada would be intercepted long before it reached the coast, and all the men drowned in the sea or, at the worst, blown to pieces with their equipment while trying to land.

As early as the end of June, some reports indicated that the enemy's plans might include the Channel, and I immediately called for inquiry.

Prime Minister to General Ismay.

27.VI.40.

It seems difficult to believe that any large force of transports could be brought to the Channel ports without our being aware of it, or that any system of mining would prevent our sweepers from clearing a way for attack on such transports on pa.s.sage. However, it would be well if the Chiefs of the Staff gave their attention to this rumour.

Anyhow, the possibility of a cross-Channel invasion, improbable though it was at that time, had to be most closely examined. I was not entirely satisfied with the military dispositions. It was imperative that the Army should know the exact task a.s.signed to it, and above all should not fritter away strength in a sedentary dispersion along the threatened coasts or exhaust the national resources by manning unduly all the coasts. Therefore I wrote:

Prime Minister to General Ismay.

28.VI.40.

Note by the Prime Minister to C.O.S. Committee.1. See papers by Vice-Chiefs of Staff and further papers by C.O.S. Committee.2. It is prudent to block off likely sections of the beaches with a good defence and to make secure all creeks and harbours on the east coast. The south coast is less immediately dangerous. No serious invasion is possible without a harbour with its quays, etc. No one can tell, should the Navy fail, on what part of the east coast the impact will fall. Perhaps there will be several lodgments. Once these are made, all troops employed on other parts of the coastal crust will be as useless as those in the Maginot Line. Although fighting on the beaches is favourable to the defence, this advantage cannot be purchased by trying to guard all the beaches. The process must be selective. But if time permits, defended sectors may be widened and improved.3. Every effort should be made to man coast defences with sedentary troops, well sprinkled with experienced late-war officers. The safety of the country depends [however] on having a large number (now only nine, but should soon be fifteen) "Leopard" brigade groups which can be directed swiftly, i.e., within four hours, to the points of lodgment. Difficulties of landing on beaches are serious, even when the invader has reached them; but difficulties of nourishing a lodgment when exposed to heavy attack by land, air, and sea are far greater. All therefore depends on rapid, resolute engagement of any landed forces which may slip through the sea-control. This should not be beyond our means provided the field troops are not consumed in beach defences, and are kept in a high condition of mobility, crouched and ready to spring.4. In the unhappy event of the enemy capturing a port, larger formations with artillery will be necessary. There should be four or five good divisions held in general reserve to deal with such an improbable misfortune. The scale of lodgment to be antic.i.p.ated should be not more than ten thousand men landed at three points simultaneously say thirty thousand in all; the scale of air attack not more than fifteen thousand landed simultaneously at two or three points in all. The enemy will not have strength to repeat such descents often. It is very doubtful whether air-borne troops can be landed in force by night; by day they should be an easy prey [to our Air Force].5. The tank story is somewhat different, and it is right to minimise by local cannon and obstacles the landing places of tanks. The Admiralty should report upon the size, character, and speed of potential tank-carrying barges or floats, whether they will be self-propelled or towed and by what craft. As they can hardly go above seven miles an hour, they should be detected in summertime after they have started, and even in fog or haze the R.D.F. stations should give warning while they are still several hours from land. The destroyers issuing from the sally-ports must strike at these with gusto. The arrangement of stops and blocks held by local sedentary forces should be steadily developed, and anti-tank squads formed. Our own tank reserve must engage the surviving invader tanks, and no doubt it is held in a position which allows swift railing [transport by rail] to the attacked area.6. Parachutists, Fifth-Columnists, and enemy motor-cyclists who may penetrate or appear in disguise in unexpected places must be left to the Home Guard, reinforced by special squads. Much thought must be given to the [enemy] trick of wearing British uniform.7. In general I find myself in agreement with the Commander-in-Chief's plan, but all possible field troops must be saved from the beaches and gathered into the "Leopard" brigades and other immediate mobile supports. Emphasis should be laid upon the main reserve. The battle will be won or lost, not on the beaches, but by the mobile brigades and the main reserve. Until the Air Force is worn down by prolonged air fighting and destruction of aircraft supply, the power of the Navy remains decisive against any serious invasion.8. The above observations apply only to the immediate summer months. We must be much better equipped and stronger before the autumn.

In July there was growing talk and anxiety on the subject both inside the British Government and at large. In spite of ceaseless reconnaissance and all the advantages of air photography, no evidence had yet reached us of large a.s.semblies of transport in the Baltic or in the Rhine or Scheldt harbours, and we were sure that no movement either of shipping or self-propelled barges through the Straits into the Channel had taken place. Nevertheless, preparation to resist invasion was the supreme task before us all, and intense thought was devoted to it throughout our war circle and Home Command.

INVASION.

NOTE BY THE PRIME MINISTER.

Prime Minister to C.-in-C., Home Forces, C.I.G.S., and General Ismay.

10.VII.40.

I find it very difficult to visualise the kind of invasion all along the coast by troops carried in small craft, and even in boats. I have not seen any serious evidence of large ma.s.ses of this cla.s.s of craft being a.s.sembled, and, except in very narrow waters, it would be a most hazardous and even suicidal operation to commit a large army to the accidents of the sea in the teeth of our very numerous armed patrolling forces. The Admiralty have over a thousand armed patrolling vessels, of which two or three hundred are always at sea, the whole being well manned by competent seafaring men. A surprise crossing should be impossible, and in the broader parts of the North Sea the invaders should be an easy prey, as part of their voyage would be made by daylight. Behind these patrolling craft are the flotillas of destroyers, of which forty destroyers are now disposed between the Humber and Portsmouth, the bulk being in the narrowest waters. The greater part of these are at sea every night, and rest in the day. They would, therefore, probably encounter the enemy vessels in transit during the night, but also could reach any landing point or points on the front mentioned in two or three hours. They could immediately break up the landing craft, interrupt the landing, and fire upon the landed troops, who, however lightly equipped, would have to have some proportion of ammunition and equipment carried onto the beaches from their boats. The flotillas would, however, need strong air support from our fighter aircraft during their intervention from dawn onward. The provision of the air-fighter escort for our destroyers after daybreak is essential to their most powerful intervention on the beaches.2. You should see the Commander-in-Chief's (Home Fleet) reply to the question put to him by the desire of the Cabinet, i.e., what happens if the enemy cover the pa.s.sage of their invading army with their heavy warships? The answer is that, as far as we know at present, they have no heavy ships not under long repair except those at Trondheim,1 which are closely watched by our very largely superior forces. When the which are closely watched by our very largely superior forces. When the Nelson Nelson and and Barham Barham are worked up after refit in a few days' time (the 13th and 16th), it would be easily possible to make two forces of British heavy ships, either of which would be sufficiently strong; thus the danger of a northern outbreak could be contained, and at the same time a dart to the south by the Trondheim ships could be rapidly countered. Moreover, the cruisers in the Thames and Humber are themselves strong enough, with the flotillas, to attack effectively any light cruisers with which the enemy could cover an invasion. I feel, therefore, that it will be very difficult for the enemy to place large well-equipped bodies of troops on the east coast of England, whether in formed bodies or flung piecemeal on the beaches as they get across. Even greater difficulties would attend expeditions in larger vessels seeking to break out to the northward. It may further be added that at present there are no signs of any a.s.semblies of ships or small craft sufficient to cause anxiety, except perhaps in Baltic ports. Frequent reconnaissance by the air and the constant watching by our submarines should give timely warning, and our minefields are an additional obstruction. are worked up after refit in a few days' time (the 13th and 16th), it would be easily possible to make two forces of British heavy ships, either of which would be sufficiently strong; thus the danger of a northern outbreak could be contained, and at the same time a dart to the south by the Trondheim ships could be rapidly countered. Moreover, the cruisers in the Thames and Humber are themselves strong enough, with the flotillas, to attack effectively any light cruisers with which the enemy could cover an invasion. I feel, therefore, that it will be very difficult for the enemy to place large well-equipped bodies of troops on the east coast of England, whether in formed bodies or flung piecemeal on the beaches as they get across. Even greater difficulties would attend expeditions in larger vessels seeking to break out to the northward. It may further be added that at present there are no signs of any a.s.semblies of ships or small craft sufficient to cause anxiety, except perhaps in Baltic ports. Frequent reconnaissance by the air and the constant watching by our submarines should give timely warning, and our minefields are an additional obstruction.3. Even more unlikely is it that the south coast would be attacked. We know that no great ma.s.s of shipping exists in the French ports, and that the numbers of small boats there are not great. The Dover barrage is being replenished and extended to the French sh.o.r.e. This measure is of the utmost consequence, and the Admiralty are being asked to press it forward constantly and rapidly. They do not think that any important vessels, warships or transports, have come through the Straits of Dover. They do not think that any important vessels, warships or transports, have come through the Straits of Dover. Therefore, I find it difficult to believe that the south coast is in serious danger at the present time. Of course, a small raid might be made upon Ireland from Brest. But this also would be dangerous to the raiders while at sea. Therefore, I find it difficult to believe that the south coast is in serious danger at the present time. Of course, a small raid might be made upon Ireland from Brest. But this also would be dangerous to the raiders while at sea.4. The main danger is from the Dutch and German harbours, which bear princ.i.p.ally upon the coast from Dover to the Wash. As the nights lengthen, this danger zone will extend northward, but then, again, the weather becomes adverse and the "fishing-boat invasion" far more difficult. Moreover, with cloud, the enemy air support may be lacking at the moment of his impact.5. I hope, therefore, relying on the above reasoning, which should be checked with the Admiralty, that you will be able to bring an ever larger proportion of your formed divisions back from the coast into support or reserve, so that their training may proceed in the highest forms of offensive warfare and counter-attack, to bring an ever larger proportion of your formed divisions back from the coast into support or reserve, so that their training may proceed in the highest forms of offensive warfare and counter-attack, and that the coast, as it becomes fortified, will be increasingly confided to troops other than those of the formed divisions, and also to the Home Guard. I am sure you will be in agreement with this view in principle, and the only question open would be the speed of the transformation. Here, too, I hope we shall be agreed that the utmost speed shall rule. and that the coast, as it becomes fortified, will be increasingly confided to troops other than those of the formed divisions, and also to the Home Guard. I am sure you will be in agreement with this view in principle, and the only question open would be the speed of the transformation. Here, too, I hope we shall be agreed that the utmost speed shall rule.6. Air-borne attack is not dealt with in this note. It does not alter its conclusions.

It will be noted that my advisers and I deemed the east coast more likely to be attacked during July and August than the south coast. There was in fact no chance of either a.s.sault during these two months. As will presently be described, the German plan was to invade across the Channel with medium ships (four thousand to five thousand tons) and small craft, and we now know that they never had any hope or intention of moving an army from the Baltic and North Sea ports in large transports; still less did they make any plans for an invasion from the Biscay ports. This does not mean that in choosing the south coast as their target they were thinking rightly and we wrongly. The east-coast invasion was by far the more formidable if the enemy had had the means to attempt it. There could, of course, be no south-coast invasion unless or until the necessary shipping had pa.s.sed southward through the Straits of Dover and had been a.s.sembled in the French Channel ports. Of this, during July, there was no sign.

We had nonetheless to prepare against all variants, and yet at the same time avoid the dispersion of our mobile forces, and to gather reserves. This nice and difficult problem could only be solved in relation to the news and events from week to week. The British coastline, indented with innumerable inlets, is over two thousand miles in circ.u.mference, without including Ireland. The only way of defending so vast a perimeter, any part or parts of which may be simultaneously or successively attacked, is by lines of observation and resistance around the coast or frontiers with the object of delaying an enemy and meanwhile creating the largest possible reserves of highly trained mobile troops so disposed as to be able to reach any point a.s.sailed in the shortest time for strong counter-attack. When in the last phases of the war Hitler found himself encircled and confronted with a similar problem, he made, as we shall see, the gravest possible mistakes in handling it. He had created a spider's web of communications, but he forgot the spider. but he forgot the spider. With the example of the unsound French dispositions for which such a fatal penalty had just been exacted fresh in our memories, we did not forget the "ma.s.s of manoeuvre"; and I ceaselessly inculcated this policy to the utmost extent that our growing resources would allow. With the example of the unsound French dispositions for which such a fatal penalty had just been exacted fresh in our memories, we did not forget the "ma.s.s of manoeuvre"; and I ceaselessly inculcated this policy to the utmost extent that our growing resources would allow.

The views in my paper of July 10 were in general harmony with Admiralty thought, and two days later Admiral Pound sent me a full and careful statement which he and the Naval Staff had drawn up in pursuance of it. Naturally and properly, the dangers we had to meet were forcefully stated.

But in summing up Admiral Pound said: It appears probable that a total of some hundred thousand men might reach these sh.o.r.es without being intercepted by naval forces ... but the maintenance of their line of supply, unless the German Air Force had overcome both our Air Force and our Navy, seems practically impossible.... If the enemy undertook this operation, he would do so in the hope that he could make a quick rush on London, living on the country as he went, and force the Government to capitulate. but the maintenance of their line of supply, unless the German Air Force had overcome both our Air Force and our Navy, seems practically impossible.... If the enemy undertook this operation, he would do so in the hope that he could make a quick rush on London, living on the country as he went, and force the Government to capitulate.

The First Sea Lord divided the hundred-thousand maximum figure both as to enemy ports of departure and the possible impact on our coasts as in the following table: [image]

I was content with this estimate. As the enemy could not bring heavy weapons with them, and would speedily have the supply lines of any lodgments cut, the invading strength seemed even in July to be well within the capacity of our rapidly improving army. I remitted the two doc.u.ments to the Staffs and Home Command.

MIINUTE BY THE P PRIME M MINISTER15.VII.40.The Chiefs of Staff and Home Defence should consider these papers. The First Sea Lord's memorandum may be taken as a working basis, and although I personally believe that the Admiralty will in fact be better than their word, and that the invaders' losses in transit would further reduce the scale of attack, yet the preparations of the land forces should be such as to make a.s.surance doubly sure. Indeed, for the land forces the scale of attack might well be doubled, namely, 200,000 men distributed as suggested Indeed, for the land forces the scale of attack might well be doubled, namely, 200,000 men distributed as suggested [i.e., in the proportion suggested] [i.e., in the proportion suggested] by the First Sea Lord. by the First Sea Lord. Our Home Army is already at a strength when it should be able to deal with such an invasion, and its strength is rapidly increasing. Our Home Army is already at a strength when it should be able to deal with such an invasion, and its strength is rapidly increasing.I should be very glad if our plans to meet invasion on sh.o.r.e could be reviewed on this basis, so that the Cabinet may be informed of any modifications. It should be borne in mind that although the heaviest attack would seem likely to fall in the north, yet the sovereign importance of London and the narrowness of the seas in this quarter make the south the theatre where the greatest precautions must be taken. yet the sovereign importance of London and the narrowness of the seas in this quarter make the south the theatre where the greatest precautions must be taken.

There was general acceptance of this basis, and for the next few weeks we proceeded upon it. Upon the action to be taken by our main Fleet in the narrow waters precise orders were issued with which I was in full agreement. On July 20, after considerable discussion with Admiral Forbes, the Commander-in-Chief, the following decisions were promulgated by the Admiralty: (1) Their Lordships do not expect our heavy ships to go south to break up an expedition landing on our coast in the absence of any reports indicating the presence of enemy heavy ships.(2) If enemy heavy ships support an expedition, accepting the risks involved in an approach to our coast in the southern part of the North Sea, then it is essential that our heavy ships should move south against them, also accepting risks.

In order to reach more definite conclusions about the varying probabilities and scales of attack on our extended coastline, so as to avoid undue spreading of our forces, I sent the Chiefs of the Staff a further Minute early in August.

DEFENCE A AGAINST I INVASIONMINUTE BY THE PRIME MINISTER AND MINISTER OF DEFENCE5.VIII.40.Bearing in mind the immense cost in war energy and the disadvantages of attempting to defend the whole coast of Great Britain, and the dangers of being unduly committed to systems of pa.s.sive defence, I should be glad if the following notes could be borne in mind:1. Our first line of defence against invasion must be as ever the enemy's ports. Air reconnaissance, submarine watching, and other means of obtaining information should be followed by resolute attacks with all our forces available and suitable upon any concentrations of enemy shipping.2. Our second line of defence is the vigilant patrolling of the sea to intercept any invading expedition, and to destroy it in transit.3. Our third line is the counter-attack upon the enemy when he makes any landfall, and particularly while he is engaged in the act of landing. This attack, which has long been ready from the sea, must be reinforced by air action; and both sea and air attacks must be continued so that it becomes impossible for the invader to nourish his lodgments.4. The land defences and the Home Army are maintained primarily for the purpose of making the enemy come in such large numbers as to afford a proper target to the sea and air forces above mentioned, and to make hostile preparations and movements noticeable to air and other forms of reconnaissance.5. However, should the enemy succeed in landing at various points, he should be made to suffer as much as possible by local resistance on the beaches, combined with the aforesaid attack from the sea and the air. This forces him to use up his ammunition, and confines him to a limited area. The defence of any part of the coast must be measured, not by the forces on the coast, but by the number of hours within which strong counter-attacks by mobile troops can be brought to bear upon the landing places. Such attacks should be hurled with the utmost speed and fury upon the enemy at his weakest moment, which is not, as is sometimes suggested, when actually getting out of his boats, but when sprawled upon the sh.o.r.e with his communications cut and his supplies running short. It ought to be possible to concentrate ten thousand men fully equipped within six hours, and twenty thousand men within twelve hours, upon any point where a serious lodgment has been effected. The withholding of the reserves until the full gravity of the attack is known is a nice problem for the Home Command.6. It must be admitted that the task of the Navy and Air Force in preventing invasion becomes more difficult in the Narrow Seas, namely, from the Wash to Dover. This sector of the coast front is also nearest to the supreme enemy objective, London. The sector from Dover to Land's End is far less menaced, because the Navy and Air Force must make sure that no ma.s.s of shipping, still less protecting warships, can be pa.s.sed into the French Channel ports. At present the scale of attack on this wide front is estimated by the Admiralty at no more than five thousand men.2 Doubling this for greater security, it should be possible to make good arrangements for speedy counter-attack in superior numbers, and at the same time to achieve large economies of force on this southern sector, in which the beach troops should be at their minimum and the mobile reserves at their maximum. These mobile reserves must be available to move to the southeastern sectors at short notice. Doubling this for greater security, it should be possible to make good arrangements for speedy counter-attack in superior numbers, and at the same time to achieve large economies of force on this southern sector, in which the beach troops should be at their minimum and the mobile reserves at their maximum. These mobile reserves must be available to move to the southeastern sectors at short notice. Evidently this situation can be judged only from week to week. Evidently this situation can be judged only from week to week.7. When we come to the west coast of Britain, a new set of conditions rules. The enemy must commit himself to the broad seas, and there will be plenty of time, if his approach is detected, to attack him with cruisers and flotillas. The Admiralty dispositions should conform to this need. The enemy has at present no warships to escort him. Should we, for instance, care to send twelve thousand men unescorted in merchant ships to land on the Norwegian coast, or in the Skagerrak and Kattegat, in face of superior sea-power and air-power? It would be thought madness.8. However, to make a.s.surance triply sure, the Admiralty should pursue their plan of laying a strong minefield from Cornwall to Ireland, covering the Bristol Channel and the Irish Sea from southward attack. This minefield is all the more necessary now that by the adoption of the northabout route for commerce we have transferred a large part of our patrolling craft from the [south-]western approaches, which have become permanently more empty and un-watched.9. The establishment of this minefield will simplify and mitigate all questions of local defence north of its point of contact with Cornwall. We must consider this sector from Cornwall to the Mull of Cantyre as the least vulnerable to sea-borne invasion. Here the works of defence should be confined to guarding by a few guns or land torpedo tubes the princ.i.p.al harbours, and giving a moderate scale of protection to their gorges.3 It is not admissible to lavish our limited resources upon this sector. It is not admissible to lavish our limited resources upon this sector.10. North of the Mull of Cantyre to Scapa Flow, the Shetlands and the Faroes, all lies in the orbit of the main Fleet. The voyage of an expedition from the Norwegian coast would be very hazardous, and its arrival anywhere right round to Cromarty Firth would not raise immediately decisive issues. The enemy, who is now crouched, would then be sprawled. His advance would lie in difficult and spa.r.s.ely inhabited country. He could be contained until sufficient forces were brought to bear and his communications immediately cut from the sea. This would make his position all the more difficult, as the distances to any important objective are much longer and he would require considerable wheeled transport. It would be impossible to fortify all landing points in this sector, and it would be a waste of energy to attempt to do so. A much longer period may be allowed for counter-attack than in the southeast opposite London.11. From Cromarty Firth to the Wash is the second most important sector, ranking next after the Wash to Dover. Here, however, all the harbours and inlets are defended, both from the sea and from the rear, and it should be possible to counter-attack in superior force within twenty-four hours. The Tyne must be regarded as the second major objective after London, for here (and to a lesser extent at the Tees) grievous damage could be done by an invader or large-scale raider in a short time. On the other hand, the sea and air conditions are more favourable to us than to the southward.12. The Combined Staffs should endeavour to a.s.sign to all these sectors their relative scales of vulnerability and defence, both in the number of men employed in the local defence of beaches and of harbours, and also in the number of days or hours within which heavy counter-attacks should be possible. As an indication of these relative scales of attack and defence, I set down for consideration the following:[image]

The Chiefs of Staff Committee, after another review of all our information, replied to this paper by a report from Colonel Hollis, who acted as their Secretary.

DEFENCE A AGAINST I INVASION.

Prime Minister.

13.VIII.40.

The Chiefs of Staff have examined, in consultation with the Commander-in-Chief Home Forces, your Minute [of August 5], and find themselves in complete agreement with the principles enunciated in paragraphs 1 to 5.2. The Commander-in-Chief a.s.sures us that the paramount importance of immediate counter-attack upon the enemy, should he obtain a temporary footing on these sh.o.r.es, has been impressed on all ranks, and that it is his policy to bring back divisions into reserve as soon as they are adequately trained and equipped for offensive operations.3. The Chiefs of Staff also agree with your a.s.sessment of the relative scales of vulnerability to sea-borne attack of the various sectors of the coast. Indeed, it is remarkable how closely the present distribution of Home Defence divisions corresponds with your figures in paragraph 12. This is worked out as follows:4. Your theoretical scales of defence are:[image]5. A force of ten divisions, if distributed in the above proportions, would give three divisions on Sector Forth-Wash, five divisions on Sector Wash-Dover, and so on. There are, in fact, twenty-six active divisions in this island, and, if your figures are multiplied by 2.6 and compared with actual distribution of these twenty-six divisions, the following picture results:[image]6. The similarity between the two sets of figures is even closer than appears at first sight, by reason of the fact that the reserve divisions located immediately north and northwest of London are available for deployment in either the sector Wash-Dover or the sector Dover-Portsmouth, and therefore the number of "available" divisions for these two sectors is variable. A total of fifteen divisions is available on the combined sectors against your suggested requirements of 16.75.7. The Chiefs of Staff point out that your figures are based on scales of sea-borne attack, whereas the actual distribution takes into account the threat from air-borne attack as well. Thus, although we may seem at present to be slightly overinsured along the south coast, the reason for this is that our defences there can be brought under the enemy fighter "umbrella" and can be subjected to a.s.sault across the Channel at comparatively short range.

Even while these doc.u.ments were being considered and printed, the situation had begun to change in a decisive manner. Our excellent Intelligence confirmed that the "Operation Sea Lion" had been definitely ordered by Hitler and was in active preparation. It seemed certain that the man was going to try. Moreover, the front to be attacked was altogether different from, or additional to, or additional to, the east coast, on which the Chiefs of the Staff, the Admiralty and I, in full agreement, still laid the major emphasis. the east coast, on which the Chiefs of the Staff, the Admiralty and I, in full agreement, still laid the major emphasis.

But thereafter came a rapid transformation. A large number of self-propelled barges and motor-boats began to pa.s.s by night through the Straits of Dover, creeping along the French coast and gradually a.s.sembling in all the French Channel ports from Calais to Brest. Our daily photographs showed this movement with precision. It had not been found possible to relay our minefields close to the French sh.o.r.e. We immediately began to attack the vessels in transit with our small craft, and Bomber Command was concentrated upon the new set of invasion ports now opening upon us. At the same time a great deal of information came to hand about the a.s.sembly of a German Army or Armies of Invasion along this stretch of the hostile coast, of movement on the railways, and of large concentrations in the Pas de Calais and Normandy. Later on, two mountain divisions with mules evidently meant to scale the Folkestone cliffs were reported near Boulogne. Meanwhile large numbers of powerful long-range batteries all along the French Channel coast came into existence.

In response to the new menace, we began to shift our weight from one leg to the other and to improve all our facilities for moving our increasingly large mobile reserves towards the southern front. About the end of the first week of August, General Brooke, now Commander-in-Chief Home Forces, pointed out that the threat of invasion was developing equally on the south coast. All the time our forces were increasing in numbers, efficiency, mobility, and equipment.

The change in our dispositions between August and September was as follows: [image]

Thus, in the last half of September we were able to bring into action on the south coast front, including Dover, sixteen divisions of high quality, of which three were armoured divisions or their equivalent in brigades, all of which were additional to the local coastal defence and could come into action with great speed against any invasion landing. This provided us with a punch or series of punches which General Brooke was well poised to deliver as might be required; and no one more capable.

All this while we could not feel any a.s.surance that the inlets and river mouths from Calais to Tersch.e.l.ling and Heligoland, with all that swarm of islands off the Dutch and Belgian coasts (the "Riddle of the Sands" of the previous war), might not conceal other large hostile forces with small or moderate-sized ships. An attack from Harwich right round to Portsmouth, Portland, or even Plymouth, centring upon the Kent promontory, seemed to impend. We had nothing but negative evidence that a third wave of invasion, harmonised with the others, might not be launched from the Baltic through the Skagerrak in large ships. This was indeed essential to a German success, because in no other way could heavy weapons reach the landed armies or large depots of supply be established in and around store-ships stranded near the east-coast beaches.

We now entered upon a period of extreme tension and vigilance. We had, of course, all this time to maintain heavy forces north of the Wash, right up to Cromarty; and arrangements were perfected to draw from these should the a.s.sault declare itself decidedly in the south. The abundant intricate railway system of the island and our continued mastery of our home air would have enabled us to move with certainty another four or five divisions to reinforce the southern defence if it were necessary on the fourth, fifth, and sixth days after the enemy's full effort had been exposed.

A very careful study was made of the moon and the tides. We thought that the enemy would like to cross by night and land at dawn; and we now know the German Army Command felt like this too. They would also be glad of a half-moonlight on the way over, so as to keep their order and make their true landfall. Measuring it all with precision, the Admiralty thought the most favourable conditions for the enemy would arise between the 15th and 30th of September. Here also we now find that we were in agreement with our foes. We had little doubt of our ability to destroy anything that got ash.o.r.e on the Dover promontory or on the sector of coast from Dover to Portsmouth, or even Portland. As all our thoughts at the summit moved together in harmonious and detailed agreement, one could not help liking the picture which presented itself with growing definition. Here perhaps was the chance of striking a blow at the mighty enemy which would resound throughout the world. One could not help being inwardly excited alike by the atmosphere and the evidence of Hitler's intentions which streamed in upon us. There were, indeed, some who, on purely technical grounds, and for the sake of the effect the total defeat and destruction of his expedition would have on the general war, were quite content to see him try.

In July and August we had a.s.serted air mastery over Great Britain, and were especially powerful and dominant over the home counties of the southeast. The Canadian Army Corps stood most conveniently posted between London and Dover. Their bayonets were sharp, and their hearts were high. Proud would they have been to strike the decisive blow for Britain and Freedom. Similar pa.s.sions burned in all b.r.e.a.s.t.s. Vast intricate systems of fortifications, defended localities, anti-tank obstacles, block-houses, pillboxes and the like, laced the whole area. The coastline bristled with defences and batteries, and at the cost of heavier losses through reduced escorts in the Atlantic, and also by new construction coming into commission, the flotillas grew substantially in numbers and quality. We had brought the battleship Revenge Revenge and the old target-ship and dummy-battleship and the old target-ship and dummy-battleship Centurion Centurion and a cruiser to Plymouth. The Home Fleet was at its maximum strength and could operate without much risk to the Humber and even to the Wash. In all respects, therefore, we were fully prepared. and a cruiser to Plymouth. The Home Fleet was at its maximum strength and could operate without much risk to the Humber and even to the Wash. In all respects, therefore, we were fully prepared.

Finally, we were already not far from the equinoctial gales customary in October. Evidently September was the month for Hitler to strike if he dared, and the tides and the moon-phase were favourable in the middle of that month.

There was some talk in Parliament after the danger had pa.s.sed away of the "invasion scare." Certainly those who knew most were the least scared. Apart from mastery of the air and command of the sea, we had as large (if not so well equipped) an army, fresh and ardent, as that which Germany a.s.sembled in Normandy four years later to oppose our return to the Continent. In that case, although we landed a million men in the first month, with vast apparatus, and with every other condition favourable, the battle was long and severe, and nearly three months were required to enlarge the area originally seized and break out into the open field. But these were values only to be tested and known in the future.

It is time to go over to the other camp and set forth the enemy's preparations and plans as we now know them.

15.

Operation Sea Lion

Plan of the German Admiralty - Their Conditions Met by the Conquest of France and the Low Countries - Meeting with the Fuehrer of July 21 - Hitler Comprehends the Difficulties but Gives the Order - Controversy Between the German Navy and Army Staffs - Raeder and Halder at Variance The Compromise Plan Agreed - Further Misgivings of the German Admiralty - Both German Navy and Army Chiefs Cast the Burden on Goering and the Air - Goering Accepts - Hitler Postpones D-Day - British Counter-Activities - The "Cromwell" Order of September 7 - A Healthy Tonic - German Ignorance of Amphibious Warfare - Service Disunion - The Germans Stake All on the Air Battle.

SOON AFTER WAR BROKE OUT on September 3, 1939, the German Admiralty, as we have learnt from their captured archives, began their staff study of the invasion of Britain. Unlike us, they had no doubt that the only way was across the narrow waters of the English Channel. They never considered any other alternative. If we had known this, it would have been an important relief. An invasion across the Channel came upon our best-defended coast, the old sea-front against France, where all the ports were fortified and our main flotilla bases, and in later times most of our airfields and air-control stations for the defence of London, were established. There was no part of the island where we could come into action quicker or in such great strength with all three Services. Admiral Raeder was anxious not to be found wanting should the demand to invade Britain be made upon the German Navy. At the same time he asked for a lot of conditions. The first of these was the entire control of the French, Belgian, and Dutch coasts, harbours, and river mouths. Therefore, the project slumbered during the Twilight War. on September 3, 1939, the German Admiralty, as we have learnt from their captured archives, began their staff study of the invasion of Britain. Unlike us, they had no doubt that the only way was across the narrow waters of the English Channel. They never considered any other alternative. If we had known this, it would have been an important relief. An invasion across the Channel came upon our best-defended coast, the old sea-front against France, where all the ports were fortified and our main flotilla bases, and in later times most of our airfields and air-control stations for the defence of London, were established. There was no part of the island where we could come into action quicker or in such great strength with all three Services. Admiral Raeder was anxious not to be found wanting should the demand to invade Britain be made upon the German Navy. At the same time he asked for a lot of conditions. The first of these was the entire control of the French, Belgian, and Dutch coasts, harbours, and river mouths. Therefore, the project slumbered during the Twilight War.

Suddenly all these conditions were surprisingly fulfilled, and it must have been with some misgivings but also satisfaction that on the morrow of Dunkirk and the French surrender he could present himself to the Fuehrer with a plan. On May 21 and again on June 20, he spoke to Hitler on the subject, not with a view to proposing an invasion, but in order to make sure that if it were ordered the planning in detail should not be rushed. Hitler was sceptical, saying that "he fully appreciated the exceptional difficulties of such an undertaking." He also nursed the hope that England would sue for peace. It was not until the last week in June that the Supreme Headquarters turned to this idea, nor till July 2 that the first directive was issued for planning the invasion of Britain as a possible event. "The Fuehrer has decided that under certain conditions the most important of which is achieving air superiority a landing in England may take place." On July 16, Hitler issued his directive: "Since England, in spite of her militarily hopeless position, shows no sign of coming to terms, I have decided to prepare a landing operation against England, and if necessary to carry it out.... The preparations for the entire operation must be completed by mid-August." Active measures in every direction were already in progress.

The German Navy Plan, of which it is clear I had received an inkling in June, was essentially mechanical. Under the cover of heavy-gun batteries firing from Gris-Nez towards Dover, and a very strong artillery protection along the French coast in the Straits, they proposed to make a narrow corridor across the Channel on the shortest convenient line and to wall this in by minefields on either side, with outlying U-boat protection. Through this the Army was to be ferried over and supplied in a large number of successive waves. There the Navy stopped, and on this the German Army Chiefs were left to address themselves to the problem.

Considering that we could, with our overwhelming naval superiority, tear these minefields to pieces with small craft under superior air power and also destroy the dozen or score of U-boats concentrated to protect them, this was at the outset a bleak proposition. Nevertheless, after the fall of France anyone could see that the only hope of avoiding a long war, with all that it might entail, was to bring Britain to her knees. The German Navy itself had been, as we have recorded, knocked about in a most serious manner in the fighting off Norway; and in their crippled condition they could not offer more than minor support to the Army. Still, they had their plan, and no one could say that they had been caught unawares by good fortune.

The German Army Command had from the first regarded the invasion of England with considerable qualms. They had made no plans or preparations for it; and there had been no training. As the weeks of prodigious, delirious victory succeeded one another, they were emboldened. The responsibility for the safe crossing was not departmentally theirs, and, once landed in strength, they felt that the task was within their power. Indeed, already in August Admiral Raeder felt it necessary to draw their attention to the dangers of the pa.s.sage, during which perhaps the whole of the army forces employed might be lost. Once the responsibility for putting the Army across was definitely thrust upon the Navy, the German Admiralty became consistently pessimistic.

On July 21 the heads of the three Services met the Fuehrer. He informed them that the decisive stage of the war had already been reached, but that England had not yet recognised it and still hoped for a turn of fate. He spoke of the support of England by the United States and of a possible change in German political relations with Soviet Russia. The execution of "Sea Lion," he said, must be regarded as the most effective means of bringing about a rapid conclusion of the war. After his long talks with Admiral Raeder, Hitler had begun to realise what the crossing of the Channel, with its tides and currents, and all the mysteries of the sea, involved. He described "Sea Lion" as "an exceptionally bold and daring undertaking." "Even if the way is short, this is not just a river crossing, but the crossing of a sea which is dominated by the enemy. This is not a case of a single-crossing operation, as in Norway; operational surprise cannot be expected; a defensively prepared and utterly determined enemy and utterly determined enemy faces us and dominates the sea area which we must use. For the Army operation forty divisions will be required. The most difficult part will be the material reinforcements and stores. We cannot count on supplies of any kind being available to us in England." The prerequisites were complete mastery of the air, the operational use of powerful artillery in the Dover Straits, and protection by minefields. "The time of year," he said, "is an important factor, since the weather in the North Sea and in the Channel during the second half of September is very bad, and the fogs begin in the middle of October. The main operation must therefore be completed by September 15, for after that date co-operation between the Luftwaffe and the heavy weapons becomes too unreliable. But as air co-operation is decisive, it must be regarded as the princ.i.p.al factor in fixing the date." faces us and dominates the sea area which we must use. For the Army operation forty divisions will be required. The most difficult part will be the material reinforcements and stores. We cannot count on supplies of any kind being available to us in England." The prerequisites were complete mastery of the air, the operational use of powerful artillery in the Dover Straits, and protection by minefields. "The time of year," he said, "is an important factor, since the weather in the North Sea and in the Channel during the second half of September is very bad, and the fogs begin in the middle of October. The main operation must therefore be completed by September 15, for after that date co-operation between the Luftwaffe and the heavy weapons becomes too unreliable. But as air co-operation is decisive, it must be regarded as the princ.i.p.al factor in fixing the date."

A vehement controversy, conducted with no little asperity, arose in the German staffs about the width of the front and the number of points to be attacked. The Army demanded a series of landings along the whole English southern coast from Dover to Lyme Regis, west of Portland. They also desired an ancillary landing north of Dover at Ramsgate. The German Naval Staff now stated that the most suitable area for the safe crossing of the English Channel was between the North Foreland and the western end of the Isle of Wight. On this the Army Staff developed a plan for a landing of 100,000 men, followed almost immediately by 160,000 more at various points from Dover westward to Lyme Bay. Colonel-General Halder, Chief of the Army Staff, declared that it was necessary to land at least four divisions in the Brighton area. He also required landings in the area Deal-Ramsgate; at least thirteen divisions must be deployed, as far as possible simultaneously, at points along the whole front. In addition, the Luftwaffe demanded shipping to transport fifty-two A.A. batteries with the first wave.

The Chief of the Naval Staff, however, made it clear that nothing like so large or rapid a movement was possible. He could not physically undertake to escort a landing fleet across the whole width of the area mentioned. All he had meant was that within these limits the Army should pick the best place. The Navy had not enough strength, even with air supremacy, to protect more than one pa.s.sage at a time, and they thought the narrowest parts of the Straits of Dover the least difficult. To carry the whole of the 160,000 men of the second wave and their equipment in a single operation would require two million tons of shipping. Even if this fantastic requirement could have been met, such quant.i.ties of shipping could not have been accommodated in the area of embarkation. Only the first echelons could be thrown across for the formation of narrow bridgeheads, and at least two days would be needed to land the second echelons of these divisions, to say nothing of the second six divisions which were thought indispensable. He further pointed out that a broad-front landing would mean three to five and a half hours' difference in the times of high water at the various points selected. Either, therefore, unfavourable tide conditions must be accepted at some places, or simultaneous landings renounced. This objection must have been very difficult to answer.