When Winston Churchill rose to speak in the British House of Commons on June 4, 1940, the rescue of British and French troops from Dunkirk was complete.The attempts to create a second British Expeditionary Force for France could not disguise the scale of the disaster that had overcome the Allies, and Churchill made no attempt to do so. “Wars,” he insisted, “are not won by evacuations.” There was, however, “a victory inside the deliverance … gained by the air force” that had protected the hundreds of ships and prevented the enemy from gaining air superiority over the beaches. The air force, he reminded the Commons, would have a greater advantage defending Britain and thus “the cause of civilization itself will be defended by the skill and devotion of a few thousand airmen.” Churchill’s speech ended with the famous phrases heard and remembered around the world: “We shall fight on the beaches, we shall fight on the landing grounds … we shall never surrender.” However, he knew that what he called The Battle of Britain would be decided in the air.

Churchill could speak with considerable confidence about the defence of Great Britain because the Royal Air Force had devoted time, energy, resources and the best brains available to the challenge of defending the island from air attack. The Battle of Britain is often remembered as a victory won against great odds, an example of what individual bravery and fortitude can accomplish. Churchill himself popularized this view when he immortalized the pilots of Fighter Command with the words: “Never in the field of human conflict was so much owed by so many to so few.” It in no way diminishes the skill or achievement of the ‘few’ to recognize that this was a battle won by a military organization, Fighter Command, which–unlike the army or navy–was well equipped, well trained, and well prepared for precisely the kind of battle seen on ‘Eagle Day’–Aug. 15, 1940.

The story begins in December 1934, when the RAF established a committee for the Scientific Survey of Air Defence, to consider “how recent advances in scientific and technical knowledge” could improve methods of destroying hostile aircraft. Sir Henry Tizard, who chaired the committee, was a scientist of exceptional ability. Though he was skeptical of proposals to find the kind of death ray that science fiction writers so admired, he asked the country’s leading radio wave expert to comment on the matter. No such ray could be created, Robert Watson-Watt reported, but even if it could how would the aircraft you wished to destroy be located? Watson-Watt thought he could help with that problem, so Air Marshal Hugh Dowding acted promptly to establish a research and testing centre in Suffolk, U.K. Dowding’s decision to give priority to the development of radar was as decisive for his country as any event recorded in British history. The next year, Fighter Command was established with a mandate to defend the home islands. Orders were given for two new single-engined, short range fighter interceptors, the Hurricane and the Spitfire, and work on radar was further accelerated.

The first major trial of radar began in the summer of 1937, and it was quickly apparent that while a single station could give advance warning of a raid nothing could be learned about the destination. Four new radar stations were built, in the belief that simple tracking would solve this problem. But the massive air defence exercises of 1938 demonstrated that there was now too much information, most of it conflicting. The RAF was bitterly disappointed for, even with the new Hurricane, Fighter Command could not position its aircraft in time to intercept the enemy. Neville Chamberlain used this information to justify his decision to sacrifice Czechoslovakia, even though the feared knock-out blow against England by air attack was impossible without German airfields in France and Belgium.

Fortunately, science again came to the aid of Fighter Command in the form of research into the operational–as distinct from technical–aspects of radar. One of the key figures in the new field of operational research was a graduate of Dalhousie University, Harold Lardner, a radio engineer who specialized in long-distance transmission. Lardner and his colleagues worked out methods for dealing with information received from the main ‘Chain Home’ stations. They encouraged the development of ‘Chain Home Low’ radars, which tracked low-flying aircraft and worked out methods of integrating information from the Royal Observer Corps. The filter room system, which permitted Dowding and Air Marshal Keith Park to focus on the changing battle, was just one result of this work.

Lardner was selected to head the Stanmore Research Section, which reported directly to Dowding. One of his first major contributions was to provide the information and supporting graphs that Dowding used to persuade Churchill to limit the number of fighters sent to reinforce the RAF in the Battle of France. After the war Lardner, who worked quietly in Ottawa for the Defence Research Board, insisted that Dowding had a shrewd knowledge of the problem and that he had only helped by presenting the data in graphical form. Dowding, in turn, insisted that Lardner’s graphs “did the trick” with Churchill.

The Stanmore Research Section carefully analysed the early air raids on Britain and worked out the best methods of deploying and controlling fighter aircraft before the main attack began. The key to success was to ensure that Fighter Command pilots attained the tactical advantages of altitude and the use of the sun at their backs. Operational research helped Fighter Command achieve this often enough to prevent the Luftwaffe from winning the air battle. When the battle was won, and Dowding unceremoniously replaced, he wrote a note to Lardner that said: “Thanks. This war will be won by science thoughtully applied to operational methods. H.D.”

Science could shorten the odds, but the Battle of Britain still had to be fought in the skies over southern England. Canadian airmen played a major role in the events of August and September 1940. Only one Royal Canadian Air Force unit, No. 1–later 401–Squadron was in the order of battle, but RAF 242 Sqdn. was all-Canadian. Its first squadron leader, F.M. Gobeil, was the first RCAF pilot to shoot down an enemy aircraft. Gobeil was replaced by the famous Douglas Bader, Britain’s legless war ace, but the rest of 242 Sqdn. remained “all-Canadian.” Arthur Bishop’s new book The Splendid Hundred tells the individual stories of fully 100 Canadian pilots who fought in the battle.

The Germans would later insist there had never been a Battle of Britain, but the record of their intentions in 1940 is clear enough. Hitler still hoped for a British surrender but plans for Sea Lion, the invasion of the south coast of England, called for absolute air superiority over the Channel and the other German options for forcing a capitulation required the destruction of British air power, including Bomber Command and the aircraft plants.

Dowding had good intelligence on German air strength thanks to Ultra, the system of decoding German radio messages enciphered on Enigma machines. The Air Ministry had overestimated German bomber and fighter strength by a factor of four, though the actual number–3,000 aircraft–was bad enough. Still, Fighter Command began the battle with 257 Spitfires and 373 Hurricanes to the Luftwaffe’s 809 Messerschmitt Bf 109s, enough to guarantee a warm reception to the German air force.

In the first phase of the action, up until Aug. 14, the Luftwaffe lost almost twice as many aircraft as the RAF. From Eagle Day to the end of August, the delivery of new and repaired planes kept Fighter Command up to strength despite the loss of 301 aircraft. The real problem was pilot losses, 126 Hurricane and Spitfire pilots in the last 10 days of August alone. But Dowding and his Stanmore Research Section had analysed the pattern of losses; new orders were soon issued forbidding pilots to pursue German fighters out over the Channel, and instructing them to concentrate on German bombers, not the Bf 109s. The results were immediately apparent. In the ferocious battles of mid-September, just 67 pilots were lost.

“Dowding understood better than anyone that his task was to maintain air superiority over the south coast of England. More aggressive tactics such as the ‘Big Wing’ concept promoted by Bader made a good deal of sense if you wished to gamble on trying to crush the Luftwaffe, but Dowding knew that Fighter Command was all that stood between Britain and a German invasion. If he is to be criticized, it is for failing to abandon some of the forward air fields and transferring more squadrons north of the Thames–beyond the range of German fighter escorts. The battle for air superiority could easily have been fought from such bases.

However, Dowding was saved from having to make a decision by Hitler’s decision to begin attacking London on Sept. 7. Eight days later, the climax of the battle came with a massive daylight assault on London. Commemorated now as Battle of Britain Day, Sept. 15 was the moment when all the years of preparation paid off. Fighter Command dealt a devastating blow, destroying some 60 German aircraft for losses of 26 Hurricanes and Spitfires. The Luftwaffe had lost the battle for air superiority and Sea Lion was indefinitely postponed. Hitler had suffered his first defeat.