It was not Adolf Hitler that originally conceived of Operation Sea Lion. The commander of the Kriegsmarine (German Navy), Erich Raeder had hopes for the success of an invasion of England when he initially developed it in 1939. It was not until 1940, when German victories gave Hitler and the commander of his Luftwaffe, Hermann Goering , a sense that victory in England could be achieved. By mid-1940, however, the prescient Raeder had begun to realize that the invasion prospects did not look good, because the necessary naval buildup had not been instituted. So it was with a measure of regret that he begun to draw up the tactical plans for the invasion in the summer of 1940.

Raedar, being a Navy man, recognized that an amphibious invasion required naval superiority. While the British Expeditionary Force, its land army, had suffered terrible defeats on continental Europe, the British Navy still dominated the high seas, suffering little damage in its defense of Norway earlier in the year. Even the immense air power that Germany could project would not be enough to successfully carry out the invasion. Other military officers did not share this dim assessment. Walther Van Brauchitsch , the commander of the army that would conduct the invasion once ashore, believed that he could easily subdue the British forces. Furthermore, Van Brauchitsch, recognized that an absolute precondition to victory was complete dominance of the skies, a task left to Hermann Goering. Albert Kesselring, a top military advisor to Hitler, believed that victory could be achieved by a massive air drop of German parachutists. Both men recognized the vital role to be played by the Luftwaffe. The confidant commander of the Luftwaffe relished the challenge, as Germany had no trouble gaining air superiority in contiguous Europe, and a defeat of British naval and land forces through air power would be a stunning vindication of Goering's air forces. Goering believed that the relative weakness of the Kriegsmarine would be more than overcome with the stunning forces of the Luftwaffe.

The final decision lay with Hitler. The German military high command did not reflect favorably upon weakness, so the validity of Raeder's doubts were largely ignored, and the military was almost unanimous in its support for the possible plan. Hitler, feeling invincible after France, enthusiastically agreed, and issued his Directive 16. Because Hitler knew that the invasion would be won in the air, he chose his trusted comrade Goering to be the commander of the proposed operation.

When the military planning committee met to begin planning the tactics of the invasion, the first and immediate demand was air assistance in neutralizing the Royal Navy, echoing the concerns Raeder and Van Brauchitsch. With a promise from Goering that German air power was unstoppable, the planning for the invasion began. Initial plans called for a wave of 13 divisions, into two waves, the first wave having 90,000 Wehrmacht forces. They would be accompanied by numerous armaments, including 650 tanks, 4500 horses, machine guns, mortars, and anti-tank weaponry. They would be followed by a similarly armed eschelon numbering 160,000 soldiers.

The Kriegsmarine recognized the difficulty of transporting this amount of men and machinery. While there appeared to be adequate shipping to get the weaponry to England, there appeared to be no way to move it to the shore. There was a severe shortage of landing craft, and the possibility of converting barges used on the Rhine looked unpromising. The tanks would have to be carried on barges, and shot out the back, which was, at best, an ineffective method of transport. Finally, even if an invasion could be improvised, there was little hope that the invasion could be resupplied by the battered Kriegsmarine.

A further difficulty of the invasion lay with the landing site. The Kriegsmarine could not support a large landing area. The Wehrmacht was comfortably with its spearheading "blitzkrieg" warfare, so a large landing site was not believed to be necessary, as long as Germany maintained the element of surprise, and the British were forced to defend the length of the strait. A site 20 miles long was selected, in between Hythe and Deal, incorporating the British port at Dover. Sea Lion called for extensive mining and submarine presence on both the Northern and Southern entrances to the English Channel, to prevent the interference of additional Royal Navy vessels.

The final tactical difficulty lay in the selection of a date for the invasion. Planning was reaching its peak in July; a successful invasion would have to be launched before September, unless the invasion were to be delayed until 1941, a prospect not welcomed by Hitler or Goering. The two month window was utilized by the Kriegsmarine in preparation for the impending assault. No one was relaxing, and all were preparing for war, as Goering took to the skies against England to gain the "inevitable" air superiority that was necessary for the invasion to occur.

The mood of the German Navy, that an invasion was tactically impossible, began to change as planning continued. The Kriegsmarine had remarkably success in compiling a makeshift navy by early August of 1940. Passenger ships, merchant ships, barges, large fishing boats, and ferries supported the naval vessels. Ships from the conquered lands of Holland and Belgium reinforced the German Navy, and the attack could easily be launched from these nations shores. While the transportation of the tanks and heavy weaponry remained an issue, it looked like the Navy could transport up to 300,000 troops. The Navy, given their air superiority and Luftwaffe support, might have been able to conduct an improvised invasion. The plan was not as watertight as previous German conquests, but the pure natural superiority of the German military machine would pull it off, as long as the infinite space above the naval vessels was filled with the buzz of attacking German warplanes.

It was now up to Hermann Goering's air force to neutralize the powerful RAF. The conflict developed into a decisive air engagement known as The Battle of Britain, in which a few thousand pilots saved Britain from the possibility of an invasion. The proud RAF turned the tide against the worst dictator man has ever known, and won an essential victory in the deadliest war mankind has ever seen.

It is ironic that Operation Sea Lion, a proposed naval invasion, became the impetus for a truly revolutionary development in air warfare. The Battle of Britain, in which the fate of Operation Sea Lion would be decided, pitted the practiced German Air Force, the Luftwaffe, against the scrappy but powerful Royal Air Force of the British Isles. The Luftwaffe enjoyed technical superiority, and had the benefit of previous engagements, starting with the Spanish Civil War and concluding with the Battle of France, only two months previous. In all these conflicts, the Luftwaffe had reigned supreme. The RAF, however, was fighting on its "home turf", had superior factories with which to produce aircraft, and was given a psychological edge in defending its homeland. The largest advantage of England came to be a new high tech early warning device, known as RADAR.

In is instructive to know more about the character of the head of the Luftwaffe, Hermann Goering, as many consider his egomania to be the cause of German failure in the Battle of Britain. Goering was no military genius. He served in the First World War as a fighter pilot, and served a short period as a civilian pilot, but was no master of air doctrine or military organization. He was, on the other hand, a successful and ruthless politician. The most powerful man in Germany, with the obvious exception of Adolf Hitler, Goering was a wealthy politician and businessman. He had been a Minister of Prussia, had helped found the Gestapo, and had even helped build the first concentration camp. He looked at his appointment as Reichlustfahrtminister as a chance to build on his political career. As such, he promised the war to Hitler with no strategy in which to win it.

The battle was initially conceived by German military authorities as an attempt to gain air superiority, and use this dominance to conduct Sea Lion. It developed, under Goering, into much more. It was a chance to break down English infrastructure and military superstructure. It was an opportunity to destroy the political capital of the British Isles. It was an opportunity to break the infamous English spirit of resistance. And finally, and most importantly, it was to show that an enemy could be totally subdued by air without any need for troops on the ground.

While the battle extended over a period of 3 months, historians generally divide the battle into five distinct categories.

1) Channel Battle (July 10-August 13)
2) Operation Eagle(August 13-August 24)
3) Airfield Bombing (August 24-Sept 7)
4) Battle of London (Sept 7 - Sept 30)
5) Night Bombing (Sept 30-Oct 30)

The first phase, the Channel battle, began before the issuance of Directive 16. This phase began with bombings up and down the English Coast, centered at the eventual invasion port of Dover. The largest attack took place on the day of that marks the beginning of the Battle of Britain, July 10. As well as attacking cities, the Luftwaffe attacked convoys, in an effort to stretch the British Air Force beyond its means, and weaken English defenses. For the most part, this phase of the engagement remained an air on air battle, which upset the impatient Fuhrer of Germany, who wanted to see a subdued RAF and subdued Royal Navy. This "aerial stalemate" caused Hitler to issue another directive, which called for the destruction of the RAF in "the shortest possible time", was the embryonic stage of Operation Eagle. Hitler and Goering had no knowledge of the Spitfire planes being developed by the British for their aerial defenses, or of the radar systems that gave them advance warning of German attacks. During July, 100 German bombers, and 80 German fighters were shot down, as compared to 70 British fighters.

August 13 was declared "Eagle Day" by the German military. The attacks were shifted away from British convoys and ports, and onto British airfields and radar stations. The policy of the German air force was the opposite of the German Army; instead of intense attacks on one target, Goering spread out the assaults, sending a massive number of bombers into many different British areas. The attacks were poorly coordinated and moderately successful; the Germans knocked out radar at the Ventnor station , and left a gap in Allied radar control of the Atlantic. The Germans did not, however, follow up their initial attacks with further waves of air assaults, and the damage done to the British defenses was reparable. On August 18, radar installations were attacked with minimal damage, except for the station at Kenley , which was shut down for several hours.

Seeing that damage to British land installation was minimal, on August 24, the Germans switched their focus to bombing airfields and manufacturing exclusively. Under the leadership of the likes of Adolf Galland, these attacks almost turned the tide of the battle to the Germans. Manston and North Weald, two British forward air stations, were attacked nearly destroyed on the first day of this rejuvenated bombing campaign. Soon the damage spread from airfields to the plants that were producing the superior Spitfire technology, while the bombing of the airfields resulted in the loss of Biggen Hill , the main station charged with the defense of London. For the Germans, the time to destroy British resistance looked to be near.

With the weather turning decisively colder, the time came for the Germans to launch and all-out offensive on the city of London, clearing the way for a successful execution of Operation Sea Lion. Totally miscalculating the strength of the RAF, the Germans drew the proverbial defeat from the jaws of victory.

The tactical failings are obvious when you look at a map of England. London was decisively farther inland than the vulnerable coastal cities and airfields; therefore, England was given more time to detect the onslaught and send up a fleet of Spitfires the deflect their blow. Air Marshall Hugh Dowding , the head of the British RAF charged with London's protection, took a gamble, sending out all of his forces, correctly anticipating the climax of the battle. 250 British Spitfires and Hurricanes defended the island against the great bombing aircraft of the Germans, the Heinkel , Dornier , and Junker bombers . The British fighters, the "few", fought successfully, sparing London from the great damage that Goering had anticipated, but at the loss of many fighters. For Hitler, it became apparent that Sea Lion would not be executed in 1940.

Goering still believed in the superiority of his forces, and began a campaign of night bombing in September, not in support of Sea Lion, but on its own merits. These included continued pressure on England to force negotiations, and bring destruction upon the island in lieu of an invasion. This continued for some time; by October, however, Hitler was forced to stop Operation Eagle, and turn his attention to the East.