WHAT ALL HAPPENED MARCH TO SEPTEMBER 1940
Find out what all happened March to September 1940

World War II: The Luftwaffe bombs Paris. (3. June 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)

World War II: The German 2nd Panzer Division captures the port of Boulogne-sur-Mer; the surrender of the last French and British troops marks the end of the Battle of Boulogne (25. May 1940)

An Italian submarine torpedoes and sinks the Greek cruiser Elli at Tinos harbor during peacetime, marking the most serious Italian provocation prior to the outbreak of the Greco-Italian War in October. (15. August 1940)

World War II: Axis Powers – Adolf Hitler and Benito Mussolini meet at the Brenner Pass in the Alps and agree to form an alliance against France and the United Kingdom. (18. March 1940)

World War II: Norway surrenders to German forces. (10. June 1940)

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

Chad becomes the first French colony to join the Allies under the administration of Félix Éboué, France's first black colonial governor. (26. August 1940)

World War II: Operation Ariel begins – Allied troops start to evacuate France, following Germany's takeover of Paris and most of the nation. (15. June 1940)

Denmark leaves the League of Nations. (20. July 1940)

World War II: The Soviet Union formally annexes Latvia. (5. August 1940)

World War II: under the Molotov-Ribbentrop Pact, the Soviet Union presents an ultimatum to Romania requiring it to cede Bessarabia and the northern part of Bukovina. (26. June 1940)

King Carol II of Romania abdicates and is succeeded by his son Michael. (6. September 1940)

The Second Vienna Award re-assigns the territory of Northern Transylvania from Romania to Hungary. (30. August 1940)

World War II: After fierce fighting, the poorly trained and equipped Dutch troops surrender to Germany, marking the beginning of five years of occupation. (15. May 1940)

The United States' Under Secretary of State Sumner Welles issues a declaration on the U.S. non-recognition policy of the Soviet annexation and incorporation of three Baltic states: Estonia, Latvia and Lithuania. (23. July 1940)

World War II: Operation Weserübung – Germany invades Denmark and Norway. (9. April 1940)

Indian independence leader Subhas Chandra Bose is arrested and detained in Calcutta. (2. July 1940)

World War II: German fighters accidentally bomb the German city of Freiburg. (10. May 1940)

World War II: Norwegian refugees form a government-in-exile in London (5. May 1940)