Great Britain, lying just a few miles off the coast of France, was extremely vulnerable to German attack, particularly from the air. Hitler was well aware of this and used it to his advantage in the two-month bombing campaign that came to be known as the Battle of Britain. (As a matter of note, though most military historians view October 31 as the formal end of the Battle of Britain, Germany continued its air assault against London through May 1941.)

Technically, Britain's involvement in the war began in 1939 when British leaders realized that Hitler could neither be calmed nor contained. His blitzkrieg invasions of Poland and France confirmed that nothing less than European domination was his ultimate goal — and it quickly became obvious that Great Britain was high on his list.

Great Britain enacted its first ever peacetime draft in July 1939, requiring all able-bodied twenty-year-old men to sign up for what was supposed to be six months of military training. However, the draftees quickly found themselves involved in an all-out war, and it would be six years before those who survived the conflict could return to civilian life.

A nationwide blackout was imposed across Great Britain on September 1, 1939, the day Hitler invaded Poland. An evacuation of the major cities was also ordered in anticipation of an air attack that failed to materialize. The United Kingdom declared war on Germany two days later, and again, Germany failed to respond with the anticipated air assault.

Britain Braces for the Worst

When war was declared, morale in Great Britain was extremely poor, thanks to a government uneasy over the idea of taking on Hitler. However, morale increased dramatically after Hitler's drive across Luxembourg toward France on May 10, 1940, and the creation that day of a coalition government under Winston Churchill. On May 22, legislation known as the Emergency Powers Act was passed requiring all British citizens to place “themselves, their services, and their property” at the disposal of the government for the conflict that was sure to come.

Plans for the rapid evacuation of children from obvious target areas and the creation of civil defense measures had been taken care of in 1939, so in 1940 the government concentrated all its efforts on strengthening and maintaining military preparedness. Over the course of the war, virtually everyone in Britain would be called on to serve the nation in one capacity or another.

Operation Sea Lion

Hitler had hoped that Great Britain would be willing to engage in peace talks after the fall of France; but the British government and military were by then well aware that Hitler's word meant nothing, and they refused to negotiate. Hitler's only recourse was a full-scale invasion of the nation, which lay just twenty miles away across the English Channel. The code name for the German invasion was Operation Sea Lion.

Great Britain's greatest defense against a German attack was the Royal Air Force (RAF). Although fewer in number than the Luftwaffe, it was nonetheless skilled, prepared, and ready to take on whatever Hitler sent its way. Germany was also briefly hobbled by the fact that the Luftwaffe was tired and in need of rearming after the earlier invasions. Stores of bombs, fuel, and other supplies needed to be set up in France if the Luftwaffe was to engage in an extended air attack. This gave Great Britain time to bolster its defenses.

While the main German air force readied itself, exploratory flights flew over England and German bombers attacked British ships offshore and laid mines in coastal waters. Great Britain responded quickly, and from July 10 to August 10, 1940, the mighty Luftwaffe lost 227 aircraft to Great Britain's 96. In many cases, RAF pilots whose planes were shot down in battle were able to parachute to safety in Britain, an option unavailable to their German adversaries.

During this period, Great Britain was able to increase the number of fighters at its disposal and, even better, discovered the secret of the German bomber navigation system, which was based on electronic beams sent from the European continent over the bombers' designated targets.

Starting August 13, 1940, code-named Eagle Day by the German military, the Luftwaffe was given six weeks to remove the threat of the RAF from the skies and soften up British ground defenses before Operation Sea Lion was put into action.

As the battle began, the RAF was able to launch slightly more than 900 Spitfire and Hurricane fighters, in addition to 84 older aircraft. Facing them was a German air force of more than 2,800 fighters and bombers divided into three air fleets: Luftflotte 2 in Belgium, the Netherlands, and northern France; Luftflotte 3 in northwestern France; and Luftflotte 5 in Norway and Denmark. Reichsmarschall Hermann Goering was placed in command of the aerial attack by Hitler, who trusted his close friend and confidant to get the job done quickly.

Things Go Badly for Germany

Germany's assault got off to a bad start. Waves of German bombers and escort fighters took off on the morning of August 13, unaware that a last-minute report of bad weather had caused Goering to delay the raids until that afternoon. Recall messages were quickly sent, but not all of the escort fighters received them. The RAF, warned by radar, was ready and waiting as the bombers approached, and shot down a considerable number.

At the end of the day, German losses totaled forty-six aircraft, with many more heavily damaged. The RAF lost thirteen fighters in the air and forty-seven planes on the ground, though only one was a fighter plane. Worse for Great Britain, the Luftwaffe had succeeded in destroying one of the radar stations on the Isle of Wight and damaging five others. The loss of the radar stations was a serious blow to the British air defense because the RAF needed them to know when and where German planes were approaching.

The German High Command was unaware of how desperately the British relied on their radar defense or how badly the bombers had damaged it. In fact, on August 15, Goering told the three air fleet commanders: “It is doubtful whether there is any point in continuing the attacks on radar sites, in view of the fact that not one of those attacked has so far been put out of operation.”

The RAF Holds Its Ground

The Battle of Britain continued, with German bombers darkening the country's skies almost every day. The first — and last — major daylight attack, by Luftflotte 5 from Norway and Denmark, occurred August 15 when the approaching air fleet was set upon by RAF Hurricanes and Spitfires over Scotland. The Luftwaffe High Command was taken by surprise, having assumed that Great Britain would be too busy defending its western coast to effectively defend Scotland. Eight German bombers and seven fighters were destroyed in the battle, and many German bombers were forced to drop their loads in the water well before their intended targets. None of the RAF fighters was lost.

Germany quickly discovered that many tactics that had worked against Poland and France were ineffective against Great Britain. For example, the Stuka dive-bombers that had inflicted so much damage on an unprepared Poland were easy targets for RAF fighters. Of the eighty-five Stukas thrown at Britain on August 17, a total of twenty-six were shot down and another fourteen were severely damaged. As a result, Goering withdrew the planes from the Battle of Britain two days later.

Despite its successes, the RAF Fighter Command found it difficult to keep up with the German air assault. From August 24 to September 6, an average of 1,000 German bombers and fighters flew over Great Britain each day. The RAF took out a great number of German aircraft and lost far fewer, but the defense was pushing the planes and their pilots to the breaking point. Exhausted pilots fell asleep as soon as their planes hit the tarmac, requiring ground crews to turn off the engines. Pilots napped while their planes were refueled and rearmed. Programs to produce new pilots were hampered by the lack of experienced instructors because all skilled pilots were in the air aiding in the defense of the nation.

The situation became increasingly dire as the battle raged on. British government and military officials knew the Fighter Command couldn't go on much longer. The defense system and the men who maintained it were on the verge of exhaustion. If the daily German raids didn't subside, there would be too few pilots and aircraft to mount an effective defense, and Germany would be free to launch a land invasion.

Germany was having problems of its own. Frustration was setting in as the sustained air attack seemed ineffective against Great Britain. On August 24, Goering decided to try a new strategy: attacking the RAF's sector control stations, which received information provided by radar, plotted the incoming raids, and sent fighters where they were most desperately needed. These stations, manned primarily by members of the RAF Women's Auxiliary Air Force, suddenly became the target of sustained air strikes.

The two-week battle took a huge toll on both sides. The RAF lost 277 fighters defending the target stations, and the Luftwaffe lost 378 aircraft. Of the 1,000-man RAF Fighter Command pilot pool, nearly a quarter were killed or wounded during this stage of the conflict.

The Assault on London

The German assault against the sector stations slowly succeeded in impeding the British air defense and almost certainly would have led to a British defeat had the attacks continued. But Goering decided on yet another change in strategy and halted the campaign against the sector stations. His new target: London itself.

The assault on London began on the afternoon of September 7. Explosive and incendiary bombs fell throughout the night, setting much of the city ablaze and sending its residents, most of them civilians, fleeing for whatever safety they could find.

That first day was just a taste of what would come. For fifty-seven consecutive nights, German bombers flew over London. The attack took a heavy toll on the city and its residents but provided some relief to battered radar sector stations and the RAF Fighter Command.

The RAF still had its hands full. Dogfights and interception runs occurred on an almost daily basis. On September 7, the RAF lost forty-one Spitfires and Hurricanes, plus a high-speed bomber known as a Blenheim. The Germans lost sixty-three aircraft in that one-day battle. Many of the air battles were fought at night, with powerful spotlights illuminating approaching German bombers.

As the Luftwaffe bombed Great Britain, RAF bombers were doing the same to Germany, with almost daily attacks on Berlin. The targets were munitions factories, gasworks, and railway yards — anything that assisted the German war effort. The bombings, which brought the conflict home for the first time to many Germans, had a serious effect on civilian and military morale.

Germany's air assault on Great Britain continued day and night through October, inflicting heavy damage but never achieving an outright victory. The RAF and the British people proved themselves far tougher than the German High Command had anticipated, and on September 17, Hitler was forced to postpone Operation Sea Lion indefinitely. Great Britain remained a German target for the rest of the war, but Germany was never able to initiate a land invasion.

On August 20, 1940, Winston Churchill acknowledged before the House of Commons the tremendous sacrifices made by RAF pilots, their support crews, and the thousands of others who worked and died to protect their homeland from invasion. As he noted, “Never in the field of human conflict was so much owed by so many to so few.”