World War II: Operation Sealion
Hitler Conquers France
By the end of June 1940, there were only two countries left to fall to the Germans in Western Europe. Firstly, there was Switzerland, the epitome of neutralism. The Germans were clearly interested in Switzerland but doubt existed whether it offered more as a conquered prize or as a neutral neighbour. Britain however, presented a more prestigious prize to Hitler, but also presented the greatest danger at the time to his grand plans for total domination. Britain was equipped with an industrial base completely out of proportion to its size and the resources of a world empire, both in terms of manpower and supplies.
Moreover, it possessed a formidable tradition of waging war by land and particularly sea; most people living at that time still remembered the time when Britain truly ruled the waves. But now in the summer of 1940 Britain stood seemingly shocked and bewildered by the events of the previous couple of months in the Low Countries and France. Hitler’s Wehrmacht had swept across Western Europe in just a matter of weeks; they had trounced the British Expeditionary Force (BEF) so utterly profoundly that there was widespread shock and disbelief that they were allowed to survive. Operation Sickle Cut had cut the British off so swiftly that the Commander if II Corps, General Alan Brooke is on record saying ‘Nothing but a miracle can save the BEF now.’
Somehow Brooke got his miracle, or at least a miracle of some sort. More than a quarter of a million Allied soldiers were evacuated from the beaches of Dunkirk between the 26th May and the 4th June. In failing to eliminate these fighting men, the Germans committed a grave error. In the long run, it would prove to be a fatal error that would come back to haunt them. However, it’s important to remember that at the time the Germans would have regarded Britain’s land forces with contempt and irrelevance. It was easier for the Fuhrer to overlook them.
But while Hitler had good reason to write off the British Army; his failure to take into account the evacuations morale raising power is virtually inexcusable. Even to this day, we Britons still speak of the Dunkirk spirit. My granddad was one of the 300,000 or so troops extricated from the beaches and would always recall his experiences with a sort of solemn pride, before going misty eyed as he recalled a fallen comrade or two.
The BEF’s evacuation had been led by the Royal Navy but probably wouldn’t have been possible without the assistance of the ‘little ships,’ these included ferries, fishing boats, tugs and even sailing yachts and cabin cruisers which all helped carry soldiers to safety. Amazingly all of these ‘little ships’ were manned entirely by their civilian volunteers. The excitement of the experience produced a national adrenaline surge, the Brits were exhilarated by the skin of the teeth heroics witnessed on the beaches of Dunkirk.
The Miracle of Dunkirk
An Amphibious Invasion
Hitler’s plans for Operation Sealion, as recorded in his Directive No. 16 were issued on the 16th July. In it he stated:
‘Since Britain shows no sign of being prepared to come to an agreement despite her desperate military situation. I have resolved to prepare- and, should it be necessary, pursue- an amphibious operation against England.
The point of this operation will be to prevent the English homeland from being used as a base for the continuation of the war against Germany. If need be, the whole island might be occupied.’
The amphibious force referred to was to move along a 'broad front' stretching from Ramsgate to the Isle of Wight. This far from the continent, the Luftwaffe would have to provide a substitute for artillery, while the navy would have to take on the role of engineers. This is what Hitler thought at least, he also stated that all of the different branches of the German military should think things through from their own perspectives. If any advance operations such as the occupation of the Isle of Wight or Cornwall, were going to be needed to make the landing possible, then this was the time to plan them. Though of course, the final decision to proceed lay with him.
The start of Hitler’s Directive states ‘Since Britain shows no sign of being able to come to an agreement...’ An interesting way to start an invasion directive against your sole remaining enemy; was there perhaps a hint of wistfulness in the Fuhrer’s tone? Had Hitler been hoping that Britain would rethink their position and spare themselves further bloodshed?
That almost certainly seems to be the case when he made the ‘Last Appeal to Reason’ in the Reichstag on the 19th July 1940. Copies of Hitler’s transcript were showered right across south-eastern England from German planes. The Nazis, he insisted had only ever wanted to free Germany from the unjust penalties laid upon it by the Versailles Treaty and also from the ‘fetters of a small substratum of Jewish-capitalist and pluto-democratic profiteers. Surely right thinking Englishmen and women would see the justice in this fight.
While it would be incorrect to describe Hitler as an Anglophile, he was a big admirer of the British imperial achievement. Even while the Battle of France raged relentlessly, he spoke in flattering terms about the ‘civilisation’ that Britain had given to the world. All in all, the formulation and nature of Operation Sealion seemed a bit slap-dashed and rushed; but why? Well, the truth was that Hitler’s heart just wasn’t it and ultimately that proved to be one of the biggest reasons why firstly the BEF were allowed to escape and why ultimately the Sealion failed to swim.
The Invasion Plan
Preparations and Dilemmas
Hitler ordered that preparations had to be completed by the middle of August, so basically he gave his senior officers four weeks to get everything into order. In that time, the Fuhrer noted, that certain key conditions had to be met:
- The RAF had to be neutralised, both physically and in morale. Hitler needed assurances that it would be unable to put up any significant resistance to the German invasion
- All sea lanes had to be cleared.
- The entrances to the Straits of Dover and the western approach to the Channel in a line running from Alderney to Portland had to be closed off by minefields.
- The landing zones had to be covered by heavy artillery on the continental coast.
- The British naval forces had to be kept occupied both in the North Sea and by the Italians in the Mediterranean for the period before the invasion.
All of these conditions boiled down to the same thing; the English Channel effectively had to become some sort of German pond, a place where vast numbers of troops could simply make their way across easily and safely. The shores too had to be under German control.
These conditions were all the more important because the Germans didn't have any purpose built landing craft to call upon. Hitler hoped to do the whole thing using canal and river barges. Of the two thousand or so craft his Kreigsmarine had managed to commandeer in Germany and the occupied countries, only a third were engine powered, and those engines were designed for use in sheltered inland waterways only. The remainder would have to be towed across the Channel by tugs and other powered sea vehicles. Moreover, when they finally reached their destination, they would have to be painstakingly manoeuvred into position so that the troops on board could disembark safely. Also, the tanks, trucks, heavy equipment and other materials needed to be unloaded without loss. These are not the kind of manoeuvres that one can achieve under heavy fire or in heavy seas. It may seem that Operation Sealion failed due to impracticality, but it might have worked had the right conditions prevailed at the time.
The difficulties facing the operation had been identified as early as 1939, when army chiefs drew up their own plans for an amphibious invasion of England in the study document Nordwest. They identified Belgium as the starting pointing point, with the landing site much further north, along the East Anglian coast. But these preliminary plans received a scornful rejection from Herman Goring. The Reichsmarschall was so pessimistic about the prospect of any invasion that he said it ‘could only be the final conclusion of an already victorious war with Britain.’ Any resistance met would be too much, he felt for what was bound to be a slow and cumbersome and mostly defenceless invasion force.
The Landing Craft
Despite a certain degree of pessimism among the German high command it should be noted that circumstances actually favoured the Germans. They had complete control of the Pas de Calais coast in northern France, so it was easy enough to bring up big guns that could pound British ships in the Channel, and even to some extent the southern English coast. The largest of these formidable guns, the K12 had an 8 inch barrel and a range of 71 miles, meaning that even from the Pas de Calais, the Germans could conceivably shell London. There were four permanent batteries, fortified with concrete that were placed in positions that ensured that every square inch of the Channel was covered. The Germans also brought several mobile batteries into play, meaning that they were able pick off any British vessels more or less at their own will. More mobile batteries were made ready for installation on the English coast just as soon as a successful landing had taken place.
The ‘broad front’ originally earmarked for landing was quickly narrowed; landing men in meaningful numbers along some 120 miles of coast would have required a force of over 160,000. So it was decided that the landing area would extend from Rottingdean, just east of Brighton, to Hythe, in southern Kent. Even this relatively short area would still require a force of some 67,000 troops.
The Kreigsmarine would provide an escort, but the emphasis would be on creating diversions in the days before the attack took place. For all the ferocity of its U-boat war, Germany’s surface navy was small and weak. Particularly in comparison with that of an island nation that, despite its beleaguered state was still strong. Britain could still boast that it ruled most of the waves, and had done so virtually unopposed for two centuries. There was nothing to be gained from taking on the Royal Navy in a straight fight. So it was hoped that the diversionary sorties to be carried out by the cruiser Admiral Hipper in the Atlantic between Iceland and the Faroe islands would effectively draw away British naval vessels.
Foiled by the Few
Hitler can at least be commended on having spotted the main weakness of his own scheme; the RAF needed to be neutralised at least, preferably destroyed. In the event, those brave men, that Churchill would later call the ‘Few’ took to the air in July 1940 in response to wave after relentless wave of German attacks. The Battle of Britain would decide whether the land of Shakespeare, Newton and Darwin would remain a free country.
Several weeks later, the Luftwaffe, the key component to the success of Operation Sealion had been driven from the English skies. Britain had saved itself from invasion and gained precious time. The rest is, as they usually say history. Operation Sealion retreated to the confines of historical ‘what if’s’ and in late September, Hitler officially dropped the operation, in a rather quiet and hushed up way.
Two Recommended Articles
- The Forgotten Few: Polish Airmen Fought During the Battle of Britain
Polish airmen fought valiantly against marauding Messerschmitts during the Battle of Britain, only to see their contributions largely ignored at war's end as Poland was absorbed into the Communist bloc.
- A Few Americans in the Battle of Britain
Before the United States entered the war, a handful of rogue American pilots defied their country's neutrality laws.
What if Operation Sealion Had Succeeded? Part One of a Fascinating Documentary.
More by this Author
During the opening weeks of Hitler's war on the Western Front, thousands of soldiers of the British Expeditionary Force and the French First Army, with their backs to the sea, were evacuated from the beaches of Dunkirk...
Of all the great historical figures that have shaped the world down the ages. Which ten have had the most profound effect on both human and natural history.
Evolution has produced a multitude of predators down the ages, but which were the deadliest of all time?