The night of 27 July 1943. A heatwave, a dry city, and 787 RAF bombers over the crowded working-class districts east of the centre. The fires join into a firestorm that pulls air in at hurricane speed. People suffocate in the cellars. About 18,000 die before morning.
Why then
Unable to land in Europe, Britain fights Germany with bombers, and since 1942 their orders have named the morale of German workers as the target. Arthur Harris, who runs Bomber Command, believes cities can be burned out of the war. Foil strips, 'Window', blind the German radar.
What they wanted
Harris wants to prove that bombing alone can end the war. Churchill needs something to show Stalin while there is no second front. Albert Speer, running German armaments, wants the factories working and warns Hitler that six more raids like it would end the war.
What changed
About a million people flee the city, yet within months its factories are working again, and nearly half of Germany's fighters have been pulled home to defend Germany. Bombing kills some 350,000 to 600,000 people in Germany by 1945.
Still argued
Richard Overy finds the bombing slowed German production and pulled fighters from the fronts, but never broke morale as promised. Whether killing civilians on that scale was justified is argued still, and since Jörg Friedrich's The Fire in 2002, by Germans themselves.