U-38 sank the Finnish SS Signe, a straggler from convoy HN-23A.
Adolf Hitler signed the order for Unternehmen Weserübung, the German invasion of Denmark and Norway.
British submarines began to execute Vice-Admiral Horton’s plan to intercept German warships expected to be leaving naval bases bound for Norway. HMS Unity and HMS Sunfish left port.
Britain and Denmark signed a trade agreement.
Germany made another air raid on Scapa Flow.
Dutch troops were put on full alert along the German border.
Chinese troops recaptured the city of Wuyuan in the north west of the country from the Japanese.
Game day 215. USSR
The Soviet Union collected 29 new Industrial Resource Points. New industrial units were built in Ukraine and the Caucasus areas.