The Blitz turns London and Britain's cities into a nightly target
Nine months of German bombing that killed tens of thousands and never delivered the invasion it was meant to enable
Quick facts
- Location
- London and cities across Britain
- Duration
- 7 September 1940 to 16 May 1941 (about 8 months)
- Consecutive nights on London
- 57
- Worst single raid
- 10-11 May 1941: 711 tons high explosive, 2,393 incendiaries, 1,436 killed
- Casualties
- Estimates range from roughly 23,000 to over 43,000 killed
- Outcome
- Invasion of Britain (Operation Sealion) shelved; RAF Fighter Command recovered
What happened
On 7 September 1940, a day Londoners came to call Black Saturday, Luftwaffe bombers hit London directly for the first time, killing 430 people and injuring 1,600 in a single afternoon and evening raid. It was retaliation of a kind: German leadership had shifted its bombing campaign away from RAF airfields and radar stations toward cities, a change intended to break British morale and clear the way for a cross-Channel invasion. London was then bombed on 57 consecutive nights, and the campaign, which the British nicknamed the Blitz after the German word Blitzkrieg, ran for eight months into targets across the country, not just the capital. The worst single night came on 10-11 May 1941, when German bombers dropped 711 tons of high explosive and 2,393 incendiary bombs on London, killing 1,436 people in one raid alone.
Why it matters
The shift from military to civilian targets was a strategic error that historians trace directly to Britain's survival: it gave RAF Fighter Command, battered by weeks of attacks on its airfields, room to rebuild, rearm, and keep flying. Germany never gained the air superiority Operation Sealion, its planned invasion of Britain, required, and the invasion was shelved before it launched.
How we know
Bomb-damage and casualty figures come from British wartime civil defense and Air Ministry records, which is why total death toll estimates still vary: the National WWII Museum cites over 23,000 killed just from the initial 1940 phase, while other tallies covering the full nine-month campaign put the toll above 40,000. The range reflects different cutoff dates and record-keeping standards rather than a real dispute about what happened.
Sources
- World History Encyclopedia. London Blitz · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- The National WWII Museum. The Blitz of 1940 · Reputable sourcenationalww2museum.org · The domain "nationalww2museum.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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