Described by prime minister Winston Churchill as the RAF's finest hour, the Battle of Britain (10 July – 31 October 1940) was the first major military campaign in history to be fought entirely in the air. It was one of Britain's most important victories of the Second World War and is credited with preventing Germany from invading Britain. Historian Julian Humphrys takes us through some of the biggest questions and facts surrounding this pivotal aerial campaign...


When and why was the Battle of Britain fought?

Adolf Hitler aimed to force Britain to submit by bombing, naval blockade or, if necessary, invasion. But to achieve this, he needed air supremacy. So, in the summer and autumn of 1940, a few thousand airmen waged a dogged battle in the skies over Britain. Next to the later conflicts of World War II, it was a tiny affair. But the stakes were huge – resting on the result was the survival of Britain and the outcome of the entire war.

What happened during the Battle of Britain? Here are 5 key dates...

10 July 1940: Official start of the battle of Britain

The battle begins with the Kanalkampf, or Channel Battles phase, when the Germans launched sustained attacks against British shipping to prevent much-needed supplies from reaching the beleaguered British Isles.

13 August 1940: Eagle Day

With the outcome of the Kanalkampf phase of the battle inconclusive, Luftwaffe commander-in-cheif Hermann Göring makes plans for an all-out assault against Fighter Command on the British mainland.

18 August 1940: The Hardest Day

Both sides suffer their greatest number of losses so far: 69 German aircraft versus Fighter Command’s 29.

7 September 1940: The Blitz begins

Dismayed by the failure to destroy Fighter Command and incensed by a British bombing raid on Berlin, Göring turns his attention to London.

15 September 1940: Battle of Britain Day

Air Vice-Marshal Keith Park famously orders all his aircraft into the air to defend the capital, abandoning his own policy of deliberate, smaller attacks by individual squadrons.

Read more details about each date in Kate Moore's 5 key dates in the Battle of Britain

What led to the Battle of Britain?

Within a few hours of each other, on 3 September 1939, Britain and France declared war against Nazi Germany following its invasion of Poland. With the exception of a brief French incursion into Germany, a few notable naval actions and some small-scale bombing raids, the opening months of the conflict were remarkably quiet. As such, the period gained the nickname ‘the Phoney War’. In the spring of 1940, all that changed.

In April, the Germans began their conquest of Norway and then, on 10 May, they invaded France and Belgium. Bypassing the heavily fortified Maginot Line, which ran along the Franco-German border, and employing fast-moving Blitzkrieg (‘lightning war’) tactics they swept through the Ardennes before turning for the coast, cutting off hundreds of thousands of French and British soldiers at Dunkirk. Operation Dynamo, the Allied evacuation from those beaches, brought over 300,000 of them back to England. But France had been knocked out of the war, and the British had been forced to leave most of their equipment behind.

Hitler expected the British to come to terms but Winston Churchill – the new British Prime Minister – was having none of it. Scorning surrender, he demonstrated to the world (and to the US in particular) Britain’s ruthless determination to fight on by attacking the fleet of its former ally, France, to prevent it from falling into German hands.

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Faced with what he saw as stubborn intransigence on the part of Britain, Hitler planned to force its surrender by bombing, naval blockade or, as a last resort, invasion. But to do this he needed to gain mastery of the skies over Britain, which meant knocking out the Royal Air Force (RAF).

Only then could a large-enough bombing campaign be mounted to force the British to the negotiating table, or an invasion force have any chance of crossing the English Channel in the face of the powerful Royal Navy.

What did the Battle of Britain mean for Hitler’s plans?

In July 1940, Hitler ordered plans to be put in place for a seaborne invasion of Britain, which was given the code name Seelöwe or ‘Sealion’. The invasion plan was seen very much as a last resort. Hitler hoped that through blockade, bombing and the threat of an invasion, he could break the British will to fight.

Had Operation Sealion actually gone ahead, it would have been an incredibly risky undertaking. For a start, a long spell of calm weather was needed for the fragile invasion barges to cross the Channel – anything more than a mild swell and they risked being swamped. And lurking in the wings was the fearsome Royal Navy.

There was a real danger that it might attack the invasion fleet as it crossed the Channel, or cut off the German ground forces once they’d landed. Only victory in the air would have given the invasion any prospect of success, but it seems highly likely that, though it may well have suffered heavy losses from bombing, mines and U-boats, the Royal Navy would have been able to intervene decisively had the invasion been attempted.

Could Operation Sealion ever have succeeded?

The RAF’s Battle of Britain heroics are credited with saving the nation. But, argues Nick Hewitt, it was the Royal Navy’s savaging of the German fleet in the battle of Norway in the spring of 1940 that scuttled Hitler’s grand invasion plans.

"In truth, there’s little chance that Germany could have invaded England, even if the RAF had been defeated in the Battle of Britain," he says. "That’s because, some weeks earlier, Britain had already, in effect, been saved."

How strong were the RAF and Luftwaffe in July 1940?

The German Air Force, or Luftwaffe, consisted of three Luftflotten (‘Air fleets’), deployed in an arc round Britain from Normandy to Scandinavia. During the Battle of Britain they had about 2,800 aircraft, two-thirds of which were bombers. The Luftwaffe had already defeated the air forces of Poland, Belgium, the Netherlands, France, and the RAF contingent prior to Dunkirk. Its crews were experienced and confident and its commander predicted it would only take a few days to knock out the RAF.

In 1936, the RAF had been organised into four separate Commands: Training, Coastal, Bomber and Fighter. Fighter Command was organised geographically into four ‘Groups’. Air Vice-Marshal Park’s 11 Group, in the South East, would bear the brunt of the fighting. It had about 650 aircraft and 1,300 pilots at its disposal at the start of the Battle.

Fighter Command had suffered heavy losses during the Battle of France and its commander Hugh Dowding controversially refused Churchill’s request for more squadrons to be sent there, arguing that every plane was needed for the forthcoming fights over Britain.

Who were the key players?

Air Chief Marshal Sir Hugh Dowding

The commander-in-chief of Fighter Command, Dowding modernised Britain’s aerial defences, encouraged the design of modern fighter planes and supported the development of radar.

Reichsmarschall Hermann Göring

A WWI flying ace who took over the fighter wing once led by the Red Baron, Göring was Commander-in-Chief of the Luftwaffe during the Battle. In 1946, he committed suicide before he was due to be executed for war crimes.

Air Vice-Marshal Keith Park

A flying ace in WWI, New Zealand-born Park commanded the Number 11 Fighter Group – responsible for the defence of London and the Southeast, and bore the brunt of the fighting.

Generalfeldmarschall Hugo Sperrle

Sperrle was commander of Luftflotte III, which was heavily engaged during the Battle. He had previously commanded the German Condor Legion, which flew on the side of the Nationalists during the Spanish Civil War.

What was the Luftwaffe's plan?

The aims of the two sides were relatively straightforward. The Germans planned to bomb key British military, industrial and, later, civilian targets, thus devastating Britain’s ability and willingness to fight. They also reasoned that, as the RAF would have to respond to these attacks, its fighter force would be worn down until the numerically superior Luftwaffe enjoyed supremacy in the skies over Britain. Then, an invasion might just be possible.

In order to get at the bombers, the RAF first had to fight its way through a protective screen of enemy fighters. And here, the Germans enjoyed a tactical advantage.

A squadron of German Heinkel He-111 bombers mid flight
Heinkel He-111 bombers on mission over Britain in Septmeber 1940 (Photo by ullstein bild/ullstein bild via Getty Images)

The RAF had always liked close formation flying. Its three-plane V formations looked impressive, but were not very agile in battle. The Germans, on the other hand, had learnt from their experiences in the Spanish Civil War. They replaced the V with a pair of planes – one would lead while the other acted as its wingman, watching its back. Two pairs often worked together and, until the British adjusted their own tactics, these looser formations gave the Germans an edge in close combat.

However, the Germans consistently underestimated how many planes the RAF had, and how quickly it could replace those it had lost. And, like the RAF, they usually overestimated how many planes they’d shot down. As a result, they never really had a clear picture of how the battle was going.

In August, they began attacking RAF airfields, which did, in fact, put Fighter Command under severe strain. But when, in early September, they switched their sights to British cities, they did so at just the wrong time. They believed Fighter Command was on its last legs. They were wrong. When large numbers of RAF fighters inflicted heavy losses on the raids of 15 September, it was a devastating blow to Luftwaffe morale.

What common myths still surround the Battle of Britain?

One enduring belief is that the Luftwaffe commander Hermann Göring was incompetent, and his unfortunate decisions placed the Luftwaffe in an unnecessarily difficult position. Christer Bergström dispels this fallacy and five other Battle of Britain myths.

Who were 'the Few'?

RAF fighter pilots were a cosmopolitan bunch, very different to the public school ‘Tally Ho’ chaps they’re popularly seen as.

In fact, of the almost 3,000 pilots that flew during the Battle of Britain, fewer than 200 were public-school educated. The rest came from a wide variety of backgrounds – bank clerks, shop assistants and factory workers all served as fighter pilots.

What they did have in common was their youth. While a few ‘old sweats’ were over 30, the average age of an RAF fighter pilot was just 20, and many were as young as 18. At the time, you had to be 21 to vote so many of these young men were risking their lives in defence of a democracy they were not yet old enough to participate in.

Not all of the Battle of Britain pilots were British

About 20 per cent of Fighter Command’s aircrew came from overseas: New Zealanders, Canadians, Australians and South Africans took part in the Battle of Britain, and they were joined by volunteers from a variety of nations including neutral countries like Ireland and the US.

Vital contributions were also made by pilots from Nazi-occupied countries – Poles, Czechoslovakians, Belgians, Frenchmen and Austrians all flew in the Battle. Many of them were experienced fighters, often motivated by an intense hatred of the country that was oppressing their own. Although it was only operational for six weeks, the Polish No 303 Squadron shot down more German planes than any other unit.

Is the Battle of Britain overrated?

Historian Sean Lang argues that this clash of aerial supremacy is among the nine most overrated battles in history – alongside Bannockburn, Bosworth and the defeat of the Spanish Armada.

RAF pilots generally received less training than their German counterparts

At this time, all German aircrew had to undergo at least six months of basic training; British pilots rarely got more than a month. German aviators received up to 80 hours’ training at specialist bomber or fighter schools, and took part in simulation sorties and mock battles before seeing combat. RAF pilots were lucky if they got more than about 20 hours of actual flying before they were posted to an operational unit, such was Britain’s shortage of manpower.

Pilots on both sides rapidly learned that there was a world of difference between the flying they’d learned in training and flying in combat. You might have been the most elegant flier in the world but it counted for little if you couldn’t shoot straight.

Fighter planes normally had only enough ammunition for about ten seconds of sustained firing, and so often the best tactic was to get your plane as close as possible to an enemy – ideally without him seeing you – fire off a short burst of one or two seconds and then quickly move on.

Such deadly encounters often lasted moments and in these circumstances strong nerves, quick reactions and good eyesight were as important as technical flying ability.

The 'many' on the ground were as important as the 'few' in the air

"The Few, the pilots in their fighter aircraft, were one cog that made up the first fully co-ordinated air defence system in the world," writes James Holland.

"This saw modern radar, an Observer Corps, radio and a highly efficient means of collating, filtering and disseminating this information being combined with a highly developed ground control to ensure that Luftwaffe raids such as those on 14 August were intercepted and harried repeatedly."

Women played vital roles in the Battle of Britain

Many worked in factories building the aircraft that actually did the fighting while one out of every eight of the pilots in the Air Transport Auxiliary (ATA), which delivered planes to stations across the country, were female. One of these was the accomplished Amy Johnson, who died in 1941 when the aircraft she was flying crashed into the Thames estuary.

Members of the Women’s Auxiliary Air Force (WAAF) worked alongside the RAF as drivers, clerks, telephonists, cooks and orderlies. Some served at radar stations while others famously worked as plotters in the various Fighter Command operations rooms mapping friendly and enemy aircraft positions and helping to direct fighter planes. Many of the places they worked at were primary targets for German attacks. More than 750 WAAFs lost their lives during the war.

Meanwhile, women in the Army’s Auxiliary Territorial Service (ATS) worked as radar operators, and joined the crews of anti-aircraft guns and searchlight units. More than 250,000 women served in the ATS during World War II, including the future Queen Elizabeth II, who joined up while a princess at the age of 19, training as a driver and mechanic.

The Spitfire was not the only RAF fighter

For many, the sleek and slender Supermarine Spitfire is the enduring symbol of the Battle of Britain. Indeed, at the time, just a glimpse of its silhouette in the sky gave hope to those below, who knew that Fighter Command were on the scene, tackling the enemy over Britain.

But the Spitfire was not the most significant plane in the RAF: Britain's number one fighter was the Hawker Hurricane. Solid, reliable and tough, it was the first monoplane fighter to enter service with the RAF, which it did in 1937. During the Battle of Britain, Hurricanes shot down more enemy planes than all the other types of Allied aircraft combined.

Was the Battle of Britain the country’s finest hour?

"One of them, certainly," writes James Holland, "as it consigned Hitler to a long attritional war on multiple fronts – a conflict his forces were not designed to fight, and which materially meant they would always be struggling."

The Battle of Britain overlaps with the Blitz

The Blitz is the name given to the sustained bombing of British cities that began with the first massed air raid on London on 7 September 1940. It continued in one form or other for eight months, only petering out in May 1941 when the Germans began to prepare their invasion of Russia.

London came under sustained attack – it was bombed for 57 consecutive nights and by the end of October more than 250,000 Londoners were homeless.


This content first appeared in the May 2015 issue of BBC History Revealed, and curated with content from BBC History Magazine and HistoryExtra published between 2010 and 2015