Raeder initiates a study of an invasion of England

Grand Admiral Raeder, Commander-in-Chief of the Kriegsmarine, gives an order for "the possibility of invading England to be examined" as he thought Hitler might suddenly ask him for an invasion-plan at some point.

After consultation with Admiral Saalwächter, Reader sets up a small special staff for the preliminary work to study an armed conflict with Britain. The studies were the responsibility of Vice Admiral Schniewind, Chief of Staff of the Naval War Staff, and Rear Admiral Fricke, Chief of the Operations Department - both considered by Raeder as among his most competent advisors.

There were to study the possibilities of an invasion of England from the specific technical problem of transport, in addition to the overall naval and military problems. Extreme care was taken to keep the knowledge of this study limited.

The Navy would be the ones who first had to determine weather, and under what conditions, it could be carried out.

Hansjürgen Reinicke, Raeder's operations officer, reports back five days later outlining the following prerequisites:

  • Eliminating or sealing off Royal Navy forces from the lanidng and approach areas.
  • Eliminating the Royal Air Force
  • Destroying all Royal Navy units in the coastal zone.
  • Preventing British submarine action against the landing fleet.

Two weeks later a seaborne assault "on a grand scale" across the North Sea "appears to be a possible expedient for forcing the enemy to sue for peace". The Heer, and later the Luftwaffe, were uncompromisingly sceptical and it wasn't passed to the OKW.

The study is based on Hitler's Directive No. 6 which gives an objective of capturing sections of the Dutch, Belgian and French coast. The report concludes that if the conditions could be set up the British would be so demoralised that an assault would not be necessary. A landing from the North Sea on the east coast of England is preferred, though less advantageous than capturing harbours. There is no mention of a unified command or timely provision of amphibious equipment.

Raeder records:

Up until now my main endeavour had been to convince Hitler and the armed forces command that this war on commerce should be carried out on to the maximum extent of Germany's warpower and armament. Hence, any diversion of our already inadequate naval forces for some other objective would materially impair out naval campaign against the British enemy. Only if such a landing in England could be achieved without too much risk or too much difficulty - and that was highly improbable - should we deviate from our original plan.

[Date TBC]

Hitler reacts negatively to Seelöwe plan

When presented with it, Hitler's reaction to Seelöwe is unfavourable. This is probably the first time he has been presented with plans to invade England as it has not been presented to the OKW. At this stage the plan is a landing on the East coast.


The Führer and the Commander-in-Chief, Navy, discuss in private details concerning the invasion of England, on which the Naval Staff has been working since November.

Seeking guidance on U-boat strategy Raeder asks Hitler if the war was going to be decided quickly, or was it wiser to assume that it would "last some time"? Hitler favours the second assumption.

Hitler promises that, after the "main operations in France" are finished he will concentrate on the submarine and Ju 88 construction programs.

Raeder names air superiority over the Channel as the first condition of any invasion:


I named absolute mastery over the Channel by our air forces as the first condition of any landing attempt.  Furthermore, this German air superiority had not only to achieve mastery of the air, but also would have to damage the British Fleet tremendously even if it could not completely prevent its appearance on the scene.  Anything less than this would make the risk too great and the invasion unjustified.  The diversion of a huge percentage of Germany's ocean, coastal and river shipping for transport of the invasion troops, I pointed out, would greatly impair Germany's domestic economy.

Hitler listed to all that I said, but expressed no views of his own at the time except to order that for the time being no preparations for a landing be made. But in any case Hitler had now been warned that any landing in England would have to be carefully studied first, and then just as carefully planned.

Reader brings the invasion plan to Hitler to forestall it being suggested by "some irresponsible person" and Hitler jumping to the idea which would mean the Kreigsmarine would be faced with impossible tasks.

All my experience with Hitler had convinced me of the importance of giving him our own opinions of a situation before less qualified people could gain his ear.

Furthermore, we had just completed a most successful amphibious operation, over wide waters, against Norway, and many people might get the idea that a similar move could be equally successful against England.

At first glance, the jump across the Channel, whose opposite shore could easily be seen from France in good weather, would seem far less dangerous that the Norwegian landings. But any experienced naval leader would know that just the opposite was true. A long and careful preparation was absolutely necessary.

Such a landing would be extremely difficult and attended with the gravest risks. However, the development of the aeroplane for both combat and and transport purposes had brought a new element not present in previous wars, and hence the possibilities of a successful invasion were not so infinitesimal as formerly. A powerful and effective Air Force might create conditions favourable for an invasion, whether it could was not in the Navy War Staff's province.

Generals Keitel, Jodel, Commander von Puttkamer (Hitler's naval adjutant) were present at the conference.

Halder records in his diary:

The overall picture of the day shows that the big battle is in full swing.

Hydrofoils and floating bunkers with caterpillar tracks that could climb beaches are mentioned as landing craft by Raeder.

Raeder raises invasion of England with Hitler

Raeder urges the Luftwaffe to start "vigorous air attacks on British bases in order to destroy ships under construction and repair". Hitler replies he is contemplating "taking such action soon".

The preparations for an invasion of England … the locality chosen for landing … mines … shipping … special craft … air supremacy.

Raeder records no comment from Hitler but does talk about a plan to settle Jews on Madagascar and complains about a "rude telegram" from Göring sent him about a plan to invade Iceland code-named Icarus - Raeder says it will require the entire Navy.

Heretofore, apparently, no one outside the Navy had given the matter any thought. But shortly after my second report of 20 June the Supreme Command of Armed Forces suddenly began to show an unexpected interest. After the fall of France it was obvious that it would be a pertinent question as to what direction the war should take now. The last Norwegian defenders capitulated on 10 June. Norway was now in our hands. On the same day Italy entered the war on our side, and with the signing of the armistice with France on 21 June the only opponent left was England.

Keitel explains "that the demands made by the Navy have been approved at this very moment."

OKW order "The War Against England" is issued

Armed Forces High Command
WFA/Abt. L Nr. 33124/40 g.Kdos.Chefs.
Feuhrer Headquarters
2 Jul. 1940
Five copies
Top Secret
Re: Warfare against England

The Fuehrer and Supreme Commander has decided:

  1. A landing in England is possible, provided that air superiority can be attained and certain other necessary conditions fulfilled. The date of commencement is therefore still undecided. All preparations are to be begun so that the operation can be carried out as soon as possible.
  2. The High Commands of the branches of the Armed forces are to supply the following information promptly:
    • Army:

      1. Estimate of the strength of the British army in view of the planned objectives. Probably losses, especially of equipment, and the expected condition of the army after partial rearmament during the next few months.
      2. Possibilities of using artillery from the Continent for additional protection of ship concentrations and transports against British naval forces (in cooperation with the Navy).
    • Navy:

      1. Analysis of the landing possibilities for large numbers of Army troops (25 to 40 divisions) and antiarcraft units, with a description of the coastal topography of southern England and of the British naval and land defences.
      2. Statement as to which routes and what equipment could be used for troops and supply transports on such a scale with adequate safety.
        It should be kept in mind that a landing on a broad front will probably facilitate the further penetration of the Army.
      3. Information as to the type and amount of shipping pace available and the time required to make it ready.
    • Air Force:

      1. Opinion on whether and when we can reckon with achieving decisive air superiority. In this connection information of the comparative strength of the British and the German Air Forces.
      2. Which airborne forces can be used to support the operation and in what way. Transport planes should be assembled for this purpose, regardless of all other tasks.
  3. The High Commands should jointly examine all organisational questions pertaining to the landing troops arising from the necessity to limit and utilise the naval and air transport space in the best manner possible.
    The forces to be landed should be greatly superior in numbers to the British troops, especially as regards tanks; they should also be largely motorised and protected by strong antiaircraft forces.
  4. All preparations must bear in mind that the plan to invade England has not taken any sort of definite shape as yet, and that these are only preparations for a possible operation. As few people as possible of these plans.

The Chief of Staff of the Armed Forces High Command

signed: Keitel.

Raeder conference with Hitler

I reiterated to Hitler my viewpoint that an invasion of England could be considered only as a last resort, in order to bring England to negotiate for peace. To achieve this last resort I told him that in my opinion the most effective weapon was a stepped-up, effective U-boat campaign, and the next most effective means would be air attacks on convoys and other important targets, such as the port of Liverpool. In contrast to the Norwegian Campaign, I could not recommend a landing in England. Aside from absolute mastery in the air, one further requisite was a dependable, absolutely mine-free zone for the troop transports. It was impossible to say how long the creation of such a mine-free channel would take, even if it could be done, or how it could then be kept free from the menace of fresh mines dropped by enemy planes. Furthermore, the flanks of the whole transport area would have to be protected by strong and effective minefields laid by ourselves.

Lastly I called attention to the face that the job of converting and readying ordinary shipping for troop transports and supply ships would be a long and tedious job, and would cause a serious stoppage in the ordinary waterborne traffic of Germany on which both our armament program and domestic economy depended. To go ahead with any real preparations before a definite decision had been made for the landing would be completely wrong. Hitler agreed. He stated that not only was mastery of the air and absolute prerequisite, but the build-up of the submarine arm was also essential.

Conference between Raeder and Von Brauchitsch


I learned the initial strong misgivings of the General Staff had been discarded, and now the difficulties were considered relatively slight, or, at any rate, far from insurmountable.

I informed the Commander in Chief of the Army that, to the contrary, the operation entailed the greatest dangers. I pointed out that in the Norwegian landings the fate of the whole German Navy had been at state, in this case there was a serious possibility that all the troops employed in the operation might be lost.

Raeder submits his response to Directive 16

Raeder submits his response to Directive 16 in the form of a long memorandum outlining the difficulties inherent in an invasion - above all from the Royal Navy which he expected to be committed "fully and decisively" and might well cut off any forces that landed in the first wave.

The Naval War Staff delivered a detailed memorandum to the Supreme Command of Armed Forces in which it was stated that the task that would fall to the Navy was completely disproportionate to the Navy's actual strength - something that was not true of the tasks of the Army and Air Force.

The memorandum then explained in detail the difficulties in the operation:
1. The French ports from which the operation was to be mounted had been badly damaged by the recent fighting or were in other ways unsuitable;
2. The part of the Channel selected for the actual crossing presented great problems because of weather conditions, tides, and rough water;
3. The first wave of the invasion would have to be landed on the open English coast, and there were no suitable landing craft for such a landing;
4. The waters for the crossing could not be made or kept absolutely free of enemy mines; and
5. The vessels on which the troops and their supplies could not be even assembled in the embarkation points until absolute mastery of the air had been achieved.

But the most important part of the memorandum was the emphatic reminder that up until now the British had never thrown the full power of their fleet into combat. However, a German invasion of England would be a matter of life and death for the British, and they would unhesitatingly commit their naval forces, to the last ship and their last man, into an all-out fight for survival. Our Air Force alone could not be counted on to guard our transports from the British Fleet, because their operations would be dependent on the weather, if for no other reason. The Navy could support the movement by protecting the convoys to the maximum of its ability, and it could, in addition, lay protective minefields and make a diversionary attacks against the enemy. Any such minefields, however, would not offer absolute protection against such a desperate opponent and even if the first landing wave got across and ashore successfully, the enemy would still be in position to drive into the amphibious area and cut off the advance wave from reinforcements.

We in the Navy doubted that we could establish conditions that would guarantee even reasonably safe protection for a crossing of the Channel by the invasion forces. Circumstances were entirely different from those in the Norway campaign. There, surprise has been a most important factor in the operation, and even though complete surprise had not been attained, the magnitude of the operation and the wide spread of the movement among so many ports, all occupied simultaneously, had been beyond the power of the enemy to anticipate.

But in the case of England, no such surprise was possible. The major part of the transport vessels we possessed were craft designed for our inland waterways and were not even equal to limited voyages in the open sea. Many, in fact did not even have their own means of propulsion and had to be towed. To be ready in time, they would have to be assembled in the embarkation ports at the same time that the invasion troops were being assembled in the same localities. Such extensive movements could not be kept hidden from the enemy's air reconnaissance, not to speak of the very active intelligence agents he had throughout occupied territory. Hence this powerful and desperate opponent, lying just across the Channel and knowing that his very existence was at stake, would not only have advance notice of the invasion, but would be able with great accuracy to figure out just where such a landing had to take place and consequently to meet it with his entire defensive force.

It could not expected that even for a brief period our Air Force would make up for our lack of naval supremacy. Yet if this most important requisite could not be fulfilled nor all of the others, then the Navy faced an impossible task.

Hitler declares the air war to be a requirement for invasion

If the results of air warfare are unsatisfactory invasion preparations will be stopped.


First of all, success is to be achieved within the target areas of Luftflotten 2 and 3. Only a complete victory over the RAF in southern England can give us the possibility of further attacks on enemy forces stationed in the depth of the country.


[Hitler] admitted that the invasion of England would be an extremely daring enterprise. He agreed that we could not expect to effect a surprise landing, and that we would be facing a most resolute opponent who controlled the water area we had to cross. Also he conceded that to keep the invasion force of approximately 40 divisions supplied after they had landed would present the utmost difficulty. An absolute prerequisite for the whole operation would be the complete supremacy in the air and an effective minefield protection along both flanks of the crossing channel, plus the added protection of a barrage from heavy guns installed on the French side of the Straights of Dover. He concluded by saying that owing to the lateness of the seasons, the main operation would have to be completed by 16 September, and therefore if all preparations had not been completed in time for the landing to begin by the first of September, then other plans would have to be considered.

Raeder reports to Hitler on invasion progress

I pointed out to Hitler that mid-September would be the earliest date the Navy could be ready, and in doing so called his attention also to the heavy burden the operation would place on Germany's ordinary water transportation, and so the tremendous load that would fall in the ship yards. Up till now, I insisted, there existed no German air supremacy. Furthermore, I emphasised the great difference of opinion between the Supreme Commanders of the Army and Navy concerning the strength of the invasion army and the extent of the landing area. The Army was demanding the transport of 13 land divisions totalling some 260,000 men, and while this was considerably less than the originally planned 25 to 40 divisions, the Army was insisting these be landed over a very broad stretch of coast. The Navy's strength was nowhere near great enough to guard this broad landing area demanded by the Army, and if this requirement was maintained, the transports on the east and west flanks would have to go without any effective protection. The Naval War Staff therefore had to make a counter-demand that the landing be spread over as narrow a coastal front as possible. Our choice was a limited area of coast on both sides of Dover.

In addition to these two opposite views as to size of forces and width of landing area, there were further differences of opinion as to the best time of day to make the actual landing.

From its viewpoint the Army was well justified in the demands it made. But the Navy could also prove that not enough shipping could be assembled to make a crossing on such a broad scale. The Channel widened in the western half of the Army's planned landing area so that the resulting distances that had to be covered were far to great for the Navy to protect the transports and supply ships here, or to insure the necessary flow of reinforcements and additional supplies.

The OKM reports to OKW on state of preparations

The Kreigsmarine assess it has to assemble:

All the steamers, barges, lighters, tugs and even motorboats and fishing craft operating on Germany's inland waters as well as out of the seaports themselves. These would additionally need converting to transport troops.

30,000 mines, depth charges, and other material for sealing off the amphibious area.

Mount several heavy coastal batteries at Cape Griz-Nez and other points on the French coast opposite Dover.

Raeder reports to Hitler at a Joint Staff conference

Keitel, Jodl, von Brauchitsch and Halder are also present at the Berghof.

All preparations are in full swing.

Minesweeping has begun with exploratory sweeps but can be carried out according to plan only if we have air superiority. It will take three weeks if the weather is favourable... Mine-laying will begin at the end of August if we have air superiority.

Two windows are available with favourable moon and tides:

  • 20-26 August
  • 19-26 September

He concludes: "the best time for the operation, all things considered, would be May 1941."


In the presence of the Commander in Chief of the Army and the Chief of the General Staff I explained the difficulties, and called extra attention to the fact that the weather in the Channel got notoriously worse in the fall.
The British Fleet, I emphasized, undoubtedly would make its appearance. The safe transport of the troops was the most vital consideration. The Air Force could not effectively protect three beachheads stretching over 100 kilometres of coastline. Therefore, I said, the landings should be restricted to the single area at Dover, and all the efforts of the Army and Air Force should be concentrated on this single narrow space. I concluded that the wisest thing would be to postpone the invasion until May 1941.

Hitler, however, decided that the attempt should be made, and set 15 September as the date for the landing. But the actual signal for the operation to commence was not to be given until after the Air Force had made concentrated attacks on the English southern coast for a whole week. If these showed powerful effects, the landing was to be carried out; otherwise, it was to be postponed until May 1941. In any case, however, despite the Navy's warning, the preparations were to continue on the Army's plan for a broad invasion front.

Hitler remarks to the Army chiefs:

Britain's hope lies in Russia and the United States. If Russia drops out of the picture America too is lost to Britain, because elimination of Russia would tremendously increase Japan's power in the Far East.

Russia is the Far Eastern sword of Britain and the United States, pointed at Japan. Here an evil wind is blowing for Britain. Japan, like Russia, has her program which she wishes to carry through before the end of the war.

Raeder disucsses invasion front with Hitler

I took the matter directly to Hitler, and requested his personal decision as to whether the invasion was to take place on the broad front envisioned by the Army or on the narrow front advocated by the Navy. I pointed out again my opinion that Operation Sea Lion should be regarded only as a last resort in case England could not be forced to negotiate for peace by any other means.
Hitler agreed, but wanted to speak again with the Commander in Chief of the Army, as the breadth of the invasion front might be a decisive factor in the whole ensuing land campaign. At this time the strength of the military forces in England was estimated to be in excess of a million and a half men. Of these 300,000 were seasoned English, French and Canadian troops rescued from Dunkirk and some 150,000 retrieved from other continental Channel ports. They had been rearmed. The would defend the island.
The opposing views of the Army and Navy as to the breadth of the landing front were reconciled temporarily by a compromise proposal for the Supreme Command of Armed Forces. Then Hitler made the final decision that the army had to arrange its operations in accordance with what the Navy believed its own forces could achieve.
It was still an open question as to whether the Air Force would actually succeed in attaining complete mastery of the air. At the end of August, according to the reports of the Air Force, the prospects seemed very good. In reality, however, the German Air Force had attained no significant superiority over the Royal Air Force, and although some weakening of the enemy's defences was apparent, the British fighters, bombers, and, most important, minelaying planes, were still everywhere in the sky. Our own anti-aircraft defence was not good enough to prevent continuous enemy air activity over the Channel ports, with the result that our congregating shipping and our embarkation areas were under steady observation and attack. On 13 September alone we lost 80 transport barges to enemy air attacks.

Hitler postpones Unternehmen Seelöwe indefinitely

An operation in October is not ruled out but unlikely.

At a Luftwaffe conference a report titled "Air Situation, September 15" is presented that states on the 15th they had mounted over 1,000 sorties with 56 aircraft lost. They were forced to concluded that Fighter Command had adequate reserves of aircraft.

Raeder is concerned that invasion barges are being sunk by R.A.F. bombers, recently over 80 were sunk in one night. He suggests: "The present air situation does not provide the conditions for carrying out the operation, as the risk is still too great. A decision should be left over until October."

The German War Diary records: "The enemy air force is still by no means defeated; on the contrary it shows increasing activity. … The Fuhrer therefore decides to postpone Sealion indefinitely."

Two days later a directive is given to scale down preparations and barges are moved back from the Channel ports.


Even Hitler admitted that the invasion could not be made at this time, and therefore would have to be postponed. However, because of the psychological effect on the English public, the decision for the postponement was not to be made public, and the threat of a landing, plus the air attacks on London was to be kept up for its over-all effect.

I had to agree with the reasons Hitler gave, but the most satisfactory thing for me was that, with the landings postponed, the probability was that they would never be carried out. So outwardly all preparations were to be continued until 12 October, when Hitler privately me informed us that the preparations were to be carried out throughout the winter, but only to keep military and political pressure on England. If the movement was to be revived the following year, he said, he would give the necessary orders. To my mind this definitely buried any project for the invasion of England. From the first the Naval War Staff had never budged from its standpoint that an invasion across the Channel was so risky that it should be considered only as the ultimate operation in case all other measures against England Failed.