With much of continental Europe under the Axis fold by mid-1940, Adolf Hitler turned his attention to Britain, determined to subdue his pesky nemesis before marshaling his forces for a protracted campaign in the East. A plan to invade England from across the English Channel—codenamed Sea Lion—was slated to begin in August, but British air and sea power would have to be neutralized first.

To win control of the skies, Hitler’s Luftwaffe chief, Field Marshal Hermann Göring, mustered an inventory of 2,600 bombers and fighter planes. British air defenses would rely on coastal radar stations and the Royal Air Force’s Fighter Command, comprising 700 Hawker Hurricanes and Supermarine Spitfires. Britain also had a new leader after the iron-willed Winston Churchill replaced Neville Chamberlain as prime minister.

The battle began in July 1940. German bombing raids initially targeted port facilities before shifting their focus to airfields and radar stations across southern England. Despite losing an alarming number of bombers in the early weeks, the German raids were unrelenting, forcing the British pilots to fly from dawn to dusk and pushing them to the brink of exhaustion. A pivotal moment came when a small number of bombs fell on London, triggering a retaliatory strike against Berlin. The modest raid caused little damage but infuriated Hitler and humiliated Göring, who had long boasted that Allied bombs would never touch the German capital. Instead of finishing off Britain’s air defenses, Göring ordered the Luftwaffe to hammer London, targeting the city with fifty-seven consecutive nighttime raids that came to be known as the Blitz.

It was a despairing time, with nightly air raid sirens sending weary civilians into underground shelters as bombs pummeled their homes and workplaces. Casualties soared and food and heating oil dwindled as Londoners emerged each morning to find entire neighborhoods ablaze or reduced to rubble, with family members and neighbors buried underneath. Though German bombs claimed the lives of more than 43,000 civilians during the Blitz, the resolve among the British people, led by the indomitable Churchill, never faltered.

The nighttime raids also gave Fighter Command a reprieve. With their Hurricanes and Spitfires grounded in the darkness, beleaguered pilots gained needed rest, and their depleted squadrons were gradually replenished with new and repaired planes. Hoping to salvage Sea Lion, the Germans eventually resumed the attacks on Britain’s air defenses, but the RAF pilots proved resilient, downing their adversaries in increasing numbers. Having failed to quash Britain’s air power, the invasion plan was shelved, and the battle ended in a decisive setback for the Nazis.