In August 1940, Britain retaliated for an attack on London by bombing Berlin for the first of what would be many air attacks in World War II. Follow this and other major World War II events from August and September of 1940 in the timeline below.
World War II Timeline: August 20-September 11
August 20: British Prime Minister Winston Churchill offers President Franklin Roosevelt the use of military bases in the West Indies and Newfoundland.
August 23-24: The Luftwaffe bombs London. Though oil facilities east of the city are targeted, London proper sustains most of the damage. The British Royal Air Force (RAF) will retaliate two nights later, attacking Berlin for the first time.
August 28: Liverpool, England, suffers its first bomb raid.
August 31: In the greatest one-day loss for the RAF to date, the Luftwaffe takes out 38 planes and critical airfields in southern Britain.
September 5: France's Vichy government severs diplomatic ties with Holland, Luxembourg, Belgium, and Norway.
As many as 4,000 German troops perish when the transport ship Marion founders after taking a direct hit from a British torpedo.
German authorities seize Jewish-owned businesses following Luxembourg's annexation by Germany and adoption of the Nuremberg Laws.
September 6: Fascist General Ion Antonescu and his Iron Guards take control of the Romanian government. Romania's King Carol is forced to abdicate after ceding much of Transylvania.
The U.S. Navy transfers the first eight of 50 destroyers promised to the Royal Navy in exchange for U.S. bases at Bermuda and other British possessions.
September 7: The Luftwaffe turns its attention from British military to civilian targets. This is part of what will be called the Blitz.
September 10: Italian troops stage themselves in Albania prior to their planned assault on Greece.
September 11: The Luftwaffe bombs London, inflicting heavy damage on St. Paul's Cathedral and Buckingham Palace.
World War II Headlines
Below are more highlights and images that outline the events of World War II and the German Blitzkrieg in 1940.
Nazi Germany's Blitz of London kills 43,000: From September to mid-November 1940, an average of 200 Axis aircraft bombed London on every night but one. Meanwhile, Luftwaffe fighter bombers and single bombers on precision bombing missions also attacked the capital by day. Regular air raids then continued until May. Destruction was widespread and severe. This massive crater was possibly caused by one of the Luftwaffe's huge 2,500-kilogram "Max" Sprengbombe Cylindrisch bombs. Countrywide, from September 1940 to May 1941, the Blitz caused 43,000 civilian deaths and 139,000 serious injuries, as well as laying waste to many residential areas and industrial, dockland, and infrastructure facilities.
Hurricanes, Spitfires defend Britain: In 1937 the RAF's first monoplane fighter -- the Hurricane Hurricane Mark I -- entered squadron service. It boasted a top speed of more than 300 mph, eight machine guns (replaced with cannons in late 1940), and an operating radius of up to 600 miles. This formidable aircraft, together with the Spitfire (introduced in 1938), proved to be the mainstay of RAF Fighter Command during the crucial Battle of Britain. Using radar to track the approaching German bombers, RAF headquarters sent these Hurricanes and Spitfires to intercept. They inflicted crippling losses upon the Luftwaffe, which helped prevent a German invasion.
Keep reading for a World War II timeline summarizing more important events from September 1940.