Berlin, the capital of Nazi Germany, was subject to 363 air raids during the Second World War. It was bombed by the RAF Bomber Command between 1940 and 1945, the United States Army Air Forces' Eighth Air Force between 1943 and 1945, and the French Air Force in 1940 and between 1944 and 1945/as part of the Allied campaign of strategic bombing of Germany. It was also attacked by aircraft of the Red Air Force in 1941 and particularly in 1945, as Soviet forces closed on the city. British bombers dropped 45,517 tons of bombs, while American aircraft dropped 22,090.3 tons. As the bombings continued, more and more people fled the city. By May 1945, 1.7 million people (40% of the population) had fled. Prelude When the Second World War began in 1939, US President Franklin D. Roosevelt issued a request to the major belligerents to confine their air raids to military targets. The French and the British agreed to abide by the request "upon the understanding that these same rules of warfare will be scrupulously observed by all of their opponents". The British had a policy of using aerial bombing only against military targets and or infrastructure such as ports and railways of direct military importance. It was acknowledged that the aerial bombing of Germany would cause civilian casualties, but the British government renounced the deliberate bombing of civilian property outside combat zones as a military tactic. The policy was abandoned on 15 May 1940, two days after the German air attack on Rotterdam, when the Royal Air Force was given permission to attack targets in the Ruhr, including oil plants and other civilian industrial targets that aided the German war effort, such as blast furnaces that at night were self-illuminating. The first RAF raid on the interior of Germany took place on the night of 10 – 11 May (on Dortmund). The Jules Verne, a variant of the Farman F.220 of the French Naval Aviation, was the first Allied bomber to raid Berlin. On the night of 7 June 1940, it dropped eight bombs of 250 kg and eighty of 10 kg on the German capital. Between 1939 and 1942, the policy of bombing only targets of direct military significance was gradually abandoned in favour of "area bombing", the large-scale bombing of German cities to destroy housing and civilian infrastructure. Although killing German civilians was never an explicit