1939
- September 1: Germany invades Poland, initiating World War II in Europe.
- September 3: Great Britain, France, Australia, and New Zealand declare war on Germany.
- September 17: The Soviet Union invades Poland.
- September 27: Warsaw surrenders.
- November 30: The Soviet Union invades Finland.
1940
- March 12: Finland signs a peace treaty with the Soviet Union.
- April 9: Germany begins the occupation of Denmark and invades Norway.
- May 10: Germany invades Belgium, the Netherlands, and Luxembourg.
- May 10: Neville Chamberlain resigns and is replaced by Winston Churchill.
- May 15: The Netherlands surrenders to Germany.
- May 26: The British Expeditionary Force evacuates from Dunkirk.
- May 28: Belgium surrenders to Germany.
- June 10: Italy declares war on Great Britain and France.
- June 14: The Wehrmacht enters Paris.
- June 16: Marshal Philippe Pétain is named leader of the Vichy government.
- June 18: The Soviet Union invades the Baltic states.
- June 22: France signs an armistice with Germany.
- June 30: German occupation of the Channel Islands begins.
- July 10: The Battle of Britain begins.
- October 28: Italy invades Greece.
- November 22: The Ninth Italian Army is defeated by the Greeks.
1941
- February 12: The Afrika Korps begin their offensive in North Africa.
- April 4: Germany captures Benghazi.
- April 6: Germany invades Yugoslavia and Greece.
- April 13: The Soviets and Japanese sign a neutrality agreement.
- April 17: The Yugoslav army surrenders to Germany.
- April 27: Germany captures Athens.
- May 20: The airborne invasion of Crete begins.
- June 1: British forces on Crete are defeated by the Germans.
- June 8: Allied forces invade Syria.
- June 22: Operation Barbarossa begins—Germany invades the Soviet Union.
- June 28: The German Army captures the Belarus city of Minsk.
- July 15: Germany captures Smolensk.
- August 16: Germany captures Novgorod.
- September 8: The siege of Leningrad begins.
- September 19: Germany captures Kiev.
- November 3: Germany captures Kursk.
- December 5: The Germans halt their offensive against Moscow.
- December 7: Japan attacks the United States’ military base in Pearl Harbor.
- December 7: Japan declares war on the United States.
1942
- February 15: Singapore falls to the Japanese.
- July 3: Sevastopol falls to German control.
- August 26: Jews are rounded up in Lyon and the surrounding regions.
- August 26–27: Prisoners arrive at the Vénissieux camp.
- August 29: The children are smuggled out of the Vénissieux camp and hidden in Lyon.
- August 29–31: The children are sent to families in the region.
- September 6: Cardinal Gerlier shares a pastoral letter about protecting Jewish children.
- October 23: The Second Battle of El Alamein begins.
- November 8: Operation Torch begins.
1943
- January 14: The Casablanca Conference begins.
- January 23: Britain’s Eighth Army captures Tripoli.
- January 31: Germany surrenders Stalingrad.
- February 8: The Soviet Union retakes Kursk.
- February 14: The Soviet Union retakes Rostov.
- May 13: Axis powers surrender in North Africa.
- July 10: Operation Husky begins.
- July 25: Benito Mussolini’s Fascist government in Italy falls.
- September 3: Italy signs an armistice with the Allies.
- September 10: Germany occupies Rome.
- September 23: Mussolini declares the establishment of a Fascist government in northern Italy.
- September 25: The Soviet Union retakes Smolensk.
- October 13: The official Italian government declares war on Germany.
- November 6: The Soviet Union retakes Kiev.
1944
- January 6: The Soviet Union advances through Polish territory.
- January 22: The Allies land in Anzio.
- January 27: The siege of Leningrad ends.
- March 19: The Wehrmacht occupies Hungary.
- April 10: The Soviet Union takes Odesa.
- May 9: The Soviet Union takes Sevastopol.
- June 4: The Allies liberate Rome.
- June 6: The Allied landing on Normandy beaches begins.
- June 28: The United States Army takes Cherbourg.
- July 3: The Soviet Union retakes Minsk.
- July 20: Operation Valkyrie fails.
- July 24: The Allied offense against German defenses in Normandy begins.
- July 28: The Soviet Union takes Brest-Litovsk.
- August 4: The Allies liberate Florence.
- August 15: The Allies land in southern France.
- August 25: The Allies liberate Paris.
- August 28: The Allies liberate Marseille and Toulon.
- August 31: The Soviet Union takes Bucharest, the capital of Romania.
- September 2: The Allies liberate Pisa.
- September 3: The Allies liberate Brussels.
- September 3: The Allies liberate Lyon.
- September 4: The Allies liberate Antwerp.
- September 5: The Soviet Union declares war on Bulgaria.
- September 22: The Allies liberate Boulogne.
- September 30: The Allies liberate Calais.
1945
- April 30: Adolf Hitler dies by suicide.
- May 7: Nazi Germany surrenders unconditionally to the Allies. World War II ends in Europe.