Invasion Barges at Boulogne 1940.
The Norwegian campaign was a critical turning point in the Second World War, for with the conquest of western Scandinavia and the subsequent seizure of France and the Low Countries, Hitler’s writ ran from Cape Finisterre to the Arctic Circle. The Baltic supply line from Sweden was now secure, and the great landlocked sea could be used as a training and staging area for the Kriegsmarine without any fear of enemy disruption. But of far greater importance was the fact that the German navy had suddenly acquired the most immediate and broadest access to the North Atlantic. No longer would German U-boat or surface sailors have to face the daunting prospect of forcing Channel minefields or sailing the long miles around the northern tip of Scotland to escape home waters. Within a matter of a few breathless weeks the world ocean was suddenly lapping at their feet as they stood on the shores of Norway and France. One of the great ironies of history had come to pass: what had eluded a kaiser obsessed with a global vision had fallen into the lap of a führer preoccupied with a continental strategy. One hundred and thirty-five years before, another potential conqueror had stood on the shores of France and gazed across the twenty-mile Strait of Dover at England sleeping in the sun. “Let us be masters of the Strait for six hours,” Napoléon had said, “and we shall be masters of the world.” Now it was Hitler’s turn to try.
Popular belief has long held that the invasion of England never went anywhere because the German air force lost the struggle to command the skies over Kent and Sussex to the RAF the following August and September. As is so often the case, popular belief is at best half right.
Hitler’s heart was never behind the invasion of England, no matter what the circumstances; neither were most of those in the German armed services. Invading unsuspecting Norway with its two million widely scattered people possessed of no significant military force, while brilliantly conceived and executed, was a far easier prospect than trying to force a lodgment on isles harboring forty-five million aroused and determined antagonists. Moreover, Hitler’s foreign policy centered about wooing England, not conquering it, which is undoubtedly why he ordered his commanders to stop and let the Franco-British armies escape from Dunkirk. Even before he became Reichschancellor, Hitler hoped to come to some sort of grandiose world-sharing agreement with the British, and from 1938 on to the fall of France two years later this was a central theme in his policy. By early July 1940, when the führer at last (and reluctantly) ordered the Wehrmacht, Luftwaffe, and Kriegsmarine to begin planning for an amphibious and airborne assault, time was running out. Churchill had rallied his forces and people for a prolonged and desperate struggle. Of almost equal importance, the Royal Navy had laid extensive minefields off the northern French and Dutch coasts that would force the Kriegsmarine to engage in at least limited sweeping operations before any invasion fleet could reach the Channel.
The prospective German operation was code-named Seelöwe (Sealion). On August 1 the führer issued his first general directive on the subject that emphasized the need to obtain aerial superiority over the Channel and southern England and discouraged Luftwaffe attacks against the Royal Navy as diversions from the main objective. In fact, Germany’s inability to mount a serious amphibious operation, together with a gross exaggeration of the size and effectiveness of the British army awaiting the Wehrmacht in England, proved to be the decisive factors in discouraging Hitler from implementing Sealion, whose basic “problem was purely that of transport across the sea.” Colonel General Franz Halder, the army chief of staff, recalled that from July to late September 1940, most of the German navy and much of the army worked intensively in the estuaries of the Rhine, Meuse, and Scheldt, hastily constructing or converting other vessels to transport and landing craft. Armored forces trained for a cross- Channel assault in the Frisian Islands, while on the French and Dutch coasts the Ninth and Sixth Armies were engaged in “special courses for . . . assault troops.” But these activities were surrounded by an air of unreality and profound confusion. “Even at the time,” Halder later admitted, “it was hardly possible to form a clear picture of all these preparations.” The confusion was compounded by a constant alteration in details so that in the end, “plans only remained consistent in their broad outlines.”
General Gerd von Rundstedt, the acerbic army commander who was picked to lead Sealion, was even more caustic and precise in his criticism. His two-paragraph dismissal of Sealion is devastating:
The proposed invasion of England was nonsense because adequate ships were not available. They were chiefly barges which had to be brought from Germany and the Netherlands. Then they had to be reconstructed so that tanks and other equipment could be driven out of the bows. Then the troops had to learn how to embark and disembark. We looked upon the whole thing as a sort of game, because it was obvious that no invasion was possible when our navy was not in a position to cover a crossing of the Channel or carry reinforcements. Nor was the German air force capable of taking on these functions if the navy failed.
As finally conceived, Sealion would require three phases. According to Halder, Phase I, the landing on beaches between Dover and Plymouth, was to take place in several waves that would ultimately place twenty-six infantry and armored divisions on British soil.
The first wave was to be formed of fast landing craft, some crossing under their own power, others lowered from sea-going ships outside the coast defense zone. The second wave was to consist of the main body of landing craft some of which could move slowly under their own power, some of which had to be towed. The third wave was to consist of large sea-going vessels which would carry the bulk of the troops as well as their supporting tanks, engineers, signal unit, etc. Phase II provided for the crossing of the panzer and motorized divisions from Holland and of further infantry divisions from the French coast. Phase III provided for the crossing of further infantry divisions and of large supplies to form a supply base. The details of Phase II and Phase III could be worked out only after it had become clear to what extent sea-going vessels would be available after the completion of the initial phases.
In other words, Sealion would be mounted on a shoestring by a comparative few very slowly moving and thus highly vulnerable landing craft, with the prospect that an adequate supply base could not be accumulated for at least several days and possibly several weeks. Given its terms and conditions, it is doubtful that Sealion would have been mounted even if Göring’s flyers had seized control of the skies over Britain. Not only was complete air superiority essential, but so was control of the flanks of the amphibious assault, and that would have required both extensive countermining and employment of every warship that Raeder could muster. Had such control been attempted from the air alone, it would have required the Luftwaffe to destroy virtually every ship in the British fleet either before or during amphibious operations. Although it may be fairly stated on the basis of air-sea battles off Norway and later Crete that the German air force was capable of inflicting great damage on the Royal Navy, it is also true that the German flyers did not come away from their battles with the enemy unscathed. Nor, of course, did they face the entire Royal Navy, as it was assumed they would have had Sealion been attempted. A successful invasion of England would have required the entire German navy and air force, plus a large portion of the German army. This was simply too big an enterprise and too costly a gamble for a führer and his generals fixated on control of continental Europe.
Or so it seemed. In fact, British power was more fragile and German prospects consequently more promising than the führer and his commanders realized. In 1914 the Hochseeflotte had refused to immolate itself in the Channel in order to seal off the western front from British reinforcements. Twenty-six years later, according to one naval veteran of the time, the British fleet suffered the same lack of nerve. The whole system of British home defense from the time of the Armada through the Great War of 1914–1918 had “depended ultimately on a battle-fleet even though it might not be used to defeat [an] invasion directly. The British naval dispositions to oppose invasion in 1940 were initially in accordance with these principles. A flotilla of some forty destroyers and over a thousand auxiliary patrol vessels was available to patrol the Channel and the southern North Sea,” while the Home Fleet remained stationed at Scapa Flow “with six cruisers further south ready to support the flotilla.”