WHAT ALL HAPPENED JANUARY TO MAY 1940
Find out what all happened January to May 1940

Igor Sikorsky performs the first successful single-rotor helicopter flight. (24. May 1940)

Winter War: Finland signs the Moscow Peace Treaty with the Soviet Union, ceding almost all of Finnish Karelia. Finnish troops and the remaining population are immediately evacuated. (12. March 1940)

World War II: In the Le Paradis massacre, 99 soldiers from a Royal Norfolk Regiment unit are shot after surrendering to German troops; two survive. (27. May 1940)

The Russo-Finnish Winter War ends. (13. March 1940)

World War II: Altmark Incident: The German tanker Altmark is boarded by sailors from the British destroyer HMS Cossack. 299 British prisoners are freed. (16. February 1940)

Booker T. Washington becomes the first African American to be depicted on a United States postage stamp. (7. April 1940)

Members of Soviet politburo, including general secretary Joseph Stalin, sign an order for the execution of 25,700 Polish intelligentsia, including 14,700 Polish POWs, known also as the Katyn massacre. (5. March 1940)

Five people are killed in an arson attack on the offices of the communist newspaper Norrskensflamman in Luleå, Sweden. (3. March 1940)

First person killed in a German bombing raid on the UK in World War II during a raid on Scapa Flow in the Orkney Islands, James Isbister. (16. March 1940)

In a ceremony held in Berkeley, California, because of the war, physicist Ernest Lawrence receives the 1939 Nobel Prize in Physics from Sweden's Consul General in San Francisco. (29. February 1940)

McDonald's opens its first restaurant in San Bernardino, California. (15. May 1940)

World War II: Germany occupies Brussels, Belgium. (17. May 1940)

FM radio is demonstrated to the Federal Communications Commission for the first time. (5. January 1940)

Finland initiates Winter War peace negotiations (29. February 1940)

World War II: German raids on British shipping convoys and military airfields begin. (10. May 1940)

The Holocaust: The first prisoners arrive at a new concentration camp at Auschwitz. (20. May 1940)

World War II: The Siege of Calais ends with the surrender of the British and French garrison. (26. May 1940)

The 1940 Summer Olympics are cancelled due to war. (1. May 1940)

Sino-Japanese War: Japan declares Nanking capital of a new Chinese puppet government, nominally controlled by Wang Jingwei. (30. March 1940)

World War II: Germany's conquest of France begins as the German army crosses the Meuse. Winston Churchill makes his "blood, toil, tears, and sweat" speech to the House of Commons. (13. May 1940)