5th January » FM broadcasting e.g FM radio is demonstrated to the Federal Communications Commission for the first time.
7th January » Winter War: The Finnish 9th Division Battle of Raate Road named stops and completely destroys the overwhelming Soviet forces on the Raate-Suomussalmi road.
8th January » World War II: Britain Rationing in the United Kingdom called introduces food rationing.
29th January » Three trains on the Sakurajima Line, in Osaka, Japan, collide and explode while approaching Ajikawaguchi Station. 181 people are killed.
7th February » The second full length animated Walt Disney film, 'Pinocchio (1940 film) known as Pinocchio', premieres.
10th February » The Soviet Union begins mass deportations of Polish citizens from Territories of Poland annexed by the Soviet Union e.g occupied eastern Poland to Siberia.
16th February » World War II: Altmark Incident: The German tanker Altmark is boarded by sailors from the British destroyer HMS or Cossack. 299 British prisoners are freed.
27th February » Martin Kamen and Sam Ruben discover carbon-14.
29th February » For her role as Mammy in 'Gone with the Wind (film) known as Gone with the Wind', Hattie McDaniel becomes the first African American to win an Academy Award.
29th February » Finland initiates Winter War peace negotiations.
3rd March » Five people are killed in an arson attack on the offices of the Left Party (Sweden) named communist newspaper 'Norrskensflamman' in Luleå, Sweden.
5th March » Six high-ranking members of Politburo of the Central Committee of the Communist Party of the Soviet Union Soviet politburo, including General Secretary of the Communist Party of the Soviet Union General Secretary Joseph Stalin, sign an order for the execu
12th March » Winter War: Finland signs the Moscow Peace Treaty (1940) or Moscow Peace Treaty with the Soviet Union, ceding almost all of Finnish Karelia. Finnish troops and the remaining population are immediately evacuated.
16th March » 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.
18th March » 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.
23rd March » The Lahore Resolution (Qarardad-e-Pakistan or the then Qarardad-e-Lahore) is put forward at the Annual General Convention of the All India Muslim League.
30th March » Second Sino-Japanese War: Japan declares Nanjing called Nanking capital of a new Reorganized National Government of China e.g Chinese puppet government, nominally controlled by Wang Jingwei.
7th April » Booker T. Washington becomes the first African American to be depicted on a United States postage stamp.
9th April » World War II: Operation Weserübung Nazi Germany called Germany invades Denmark and Norway.
9th April » Vidkun Quisling seizes power in Norway.
14th April » World War II: Royal Marines land in Namsos, Norway in preparation for a larger force to arrive two days later.
15th April » The Allies of World War II known as Allies begin their attack on the Norway known as Norwegian town of Narvik which is occupied by Nazi Germany.
23rd April » The Rhythm Night Club fire at a dance hall in Natchez, Mississippi, kills 198 people.
1st May » The 1940 Summer Olympics are cancelled due to war.
5th May » World War II: Norwegian refugees form a government-in-exile in London
5th May » World War II: Norwegian Campaign – Norwegian squads in Battle of Hegra Fortress Hegra Fortress and Battle of Vinjesvingen Vinjesvingen capitulate to Nazi Germany German forces after all other Norwegian forces in southern Norway had laid down their arms.
6th May » John Steinbeck is awarded the Pulitzer Prize for Fiction named Pulitzer Prize for his novel 'The Grapes of Wrath'.
7th May » The Norway Debate in the British House of Commons begins, and leads to the replacement of Prime Minister Neville Chamberlain with Winston Churchill three days later.
9th May » World War II: The Nazi Germany German submarine German submarine U-9 (1935) 'U-9' sinks the French coastal submarine Doris (submarine) Doris near Den Helder.
10th May » World War II: German fighters accidentally bomb the German city of Freiburg.
10th May » World War II: Nazi Germany e.g German raids on British shipping convoys and military airfields begin.
10th May » World War II: Germany invades Battle of Belgium Belgium, the Battle of the Netherlands Netherlands and German occupation of Luxembourg in World War II Luxembourg.
10th May » World War II: Winston Churchill is appointed Prime Minister of the United Kingdom following the resignation of Neville Chamberlain.
10th May » World War II: Invasion of Iceland by the United Kingdom.
13th May » Queen Wilhelmina of the Netherlands flees her country to Great Britain after the Nazism e.g German invasion. Princess Juliana of the Netherlands named Princess Juliana takes her children to Canada for their safety.
14th May » World War II: Rotterdam is bombed by the Nazi Germany named German Luftwaffe.
14th May » World War II: The Battle of the Netherlands ends with the Netherlands surrendering to Germany.
14th May » The Yermolayev Yer-2, a long-range Soviet Union e.g Soviet medium bomber, makes its first flight.
15th May » USS Sailfish SS-192 6 is recommissioned. It was originally the USS 'Squalus'.
15th May » World War II: After fierce fighting, the poorly trained and equipped Netherlands e.g Dutch troops surrender to Nazi Germany e.g Germany, marking the beginning of five years of occupation.
17th May » World War II: Germany occupies Brussels, Belgium.
17th May » World War II: the old city centre of the Dutch town of Middelburg is bombed by the German Luftwaffe, to force the surrender of the Dutch armies in Zeeland.
20th May » The Holocaust: The first prisoners arrive at a new concentration camp at Auschwitz.
24th May » Igor Sikorsky performs the first successful single-rotor helicopter flight.
24th May » Acting on the orders of Soviet Union named Soviet leader Joseph Stalin, NKVD agent Iosif Grigulevich orchestrates an unsuccessful assassination attempt on exiled Russian revolutionary Leon Trotsky in Coyoacán, Mexico.
25th May » World War II: The German 2nd Panzer Division (Wehrmacht) named 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 (1940) known as Battle of Boulogne.
26th May » World War II: Operation Dynamo In northern France, Allies of World War II known as Allied forces begin a Dunkirk evacuation known as massive evacuation from Dunkirk, France.
26th May » World War II: The Siege of Calais (1940) e.g Siege of Calais ends with the surrender of the British and French garrison.
27th May » World War II: In the Le Paradis massacre, 99 soldiers from a Royal Norfolk Regiment unit are shot after surrendering to Nazi Germany known as German troops; two survive.
28th May » World War II: Belgium surrenders to Nazi Germany to end the Battle of Belgium.
28th May » World War II: Norway Norwegian, France French, Poland Polish and United Kingdom British forces Battles of Narvik recapture Narvik in Norway. This is the first allied infantry victory of the War.
29th May » The first flight of the Vought F4U Corsair.
3rd June » World War II: The Luftwaffe bombs Paris.
3rd June » World War II: The Battle of Dunkirk ends with a Nazi Germany called German victory and with Allies of World War II named Allied forces in full retreat.
3rd June » Franz Rademacher proposes Madagascar Plan or plans to make Madagascar the "Jewish homeland", an idea that had first been considered by 19th century journalist Theodor Herzl.
4th June » World War II: The Dunkirk evacuation ends Armed Forces of the United Kingdom called British forces complete evacuation of 338,000 troops from Dunkirk, France e.g Dunkirk in France. To rally the morale of the country, Winston Churchill delivers his famous
5th June » World War II: After a brief lull in the Battle of France, the Germans renew the offensive against the remaining French divisions south of the River Somme in Operation 'Fall Rot' ("Case Red").
7th June » Haakon VII of Norway called King Haakon VII, Olav V of Norway or Crown Prince Olav and the Norwegian government leaves Tromsø and goes into exile in London. They return exactly five years later
8th June » World War II: the completion of Operation Alphabet, the evacuation of Allied forces from Narvik at the end of the Norwegian Campaign.
10th June » World War II: Norway surrenders to Nazi Germany or German forces.
10th June » World War II: Italy declares war on France and the United Kingdom.
12th June » World War II: Thirteen thousand United Kingdom e.g British and French troops surrender to Major General Erwin Rommel at Saint-Valery-en-Caux.
14th June » World War II: Paris falls under German occupation, and Allied forces retreat.
14th June » The Soviet Union 1940 Soviet ultimatum to Lithuania named presents an ultimatum to Lithuania resulting in Lithuanian loss of independence.
14th June » A group of 728 Polish political prisoners from Tarnów become the first residents of the Auschwitz concentration camp.
16th June » A Communist government is installed in Lithuania.
17th June » The three Baltic states of Estonia, Latvia and Lithuania fall under the Occupation and annexation of the Baltic states by the Soviet Union (1940) known as occupation of the Soviet Union.
18th June » Appeal of June 18 by Charles de Gaulle.
18th June » This was their finest hour called "Finest Hour" speech by Winston Churchill.
20th June » World War II: Italy begins an Italian invasion of France called unsuccessful invasion of France.
21st June » The first successful west-to-east navigation of Northwest Passage begins at Vancouver, British Columbia, Canada.
22nd June » France is forced to sign the Armistice with France (Second Compiègne) or Second Compiègne armistice with Nazi Germany known as Germany.
23rd June » World War II: Nazi Germany called German leader Adolf Hitler surveys newly defeated Paris in now occupied France.
24th June » World War II: Operation Collar (commando raid) known as Operation Collar, the first British Commandos named British Commando raid on occupied France, by No 11 Independent Company.
25th June » World War II: France officially surrenders to Germany at 01:35.
26th June » World War II: Under the Molotov-Ribbentrop Pact, the Soviet Union presents an June 1940 Soviet Ultimatum or ultimatum to Romania requiring it to cede Bessarabia and the northern part of Bukovina.
28th June » Romania cedes Bessarabia (current-day Moldova) to the Soviet Union after Soviet occupation of Bessarabia and Northern Bukovina named facing an ultimatum.
2nd July » Indian independence leader Subhas Chandra Bose is arrested and detained in Calcutta.
3rd July » World War II: In order to stop the ships from falling into German hands the French fleet of the Atlantic based at Mers El Kébir, Attack on Mers-el-Kébir is bombarded by the British fleet, coming from Gibraltar, causing the loss of three battleships: Frenc
5th July » World War II: The United Kingdom and the Vichy France government break off diplomatic relations.
10th July » World War II: The Vichy France e.g Vichy government is established in France.
10th July » World War II: Battle of Britain The Nazi Germany named German Luftwaffe begins attacking British convoys in the English Channel thus starting the battle (this start date is contested, though).
11th July » World War II: Vichy France regime is formally established. Philippe Pétain becomes Prime Minister of France.
19th July » World War II: Battle of Cape Spada The Royal Navy and the Regia Marina clash; the Italian light cruiser Bartolomeo Colleoni Italian cruiser Bartolomeo Colleoni or Bartolomeo Colleoni sinks, with 121 casualties.
19th July » World War II: Army order 112 forms the Intelligence Corps (United Kingdom) e.g Intelligence Corps of the British Army.
20th July » California opens its first freeway, the Arroyo Seco Parkway.
25th July » General Henri Guisan orders the Military of Switzerland or Swiss Army to resist German invasion and makes surrender illegal.
27th July » The animated short 'A Wild Hare' is released, introducing the character of Bugs Bunny.
3rd August » World War II: Kingdom of Italy named Italian forces begin the Italian conquest of British Somaliland named invasion of British Somaliland.
5th August » World War II: The Soviet Union formally Soviet occupation of Latvia in 1940 1940-1941: The first Soviet occupation called annexes Latvia.
6th August » Estonia was illegally annexed by the Soviet Union.
7th August » World War II: Alsace-Lorraine is annexed by the Third Reich.
8th August » The "Aufbau Ost (1940) e.g Aufbau Ost" directive is signed by Wilhelm Keitel.
15th August » An Kingdom of Italy known as Italian submarine torpedoes and sinks the Greek cruiser Elli (1912) known as Greek cruiser 'Elli' at Tinos harbor during peacetime, marking the most serious Italian provocation prior to the outbreak of the Greco-Italian War in
19th August » First flight of the North American B-25 Mitchell e.g B-25 Mitchell medium bomber.
20th August » In Mexico City, Mexico exiled Russian revolutionary Leon Trotsky is fatally wounded with an ice axe by Ramón Mercader. He dies the next day.
20th August » World War II: Prime Minister of the United Kingdom e.g British Prime Minister Winston Churchill makes the fourth of his famous wartime speeches, containing the line "Never was so much owed by so many to so few".
30th August » The Second Vienna Award reassigns the territory of Northern Transylvania from Romania to Hungary.
31st August » Lovettsville Air Disaster called Pennsylvania Central Airlines Trip 19 crashes near Lovettsville, Virginia. The Civil Aeronautics Authority e.g CAB investigation of the accident is the first investigation to be conducted under the Bureau of Air Commerce a
6th September » King Carol II of Romania abdicates and is succeeded by his son Michael of Romania named Michael.
7th September » Treaty of Craiova: Romania loses Southern Dobruja to Bulgaria.
9th September » George Stibitz pioneers the first remote operation of a computer.
9th September » Treznea massacre: The Hungarian Army, supported by Hungarians in Romania known as local Hungarians kill 93 Romanians or Romanian civilians in Treznea, a village in Northern Transylvania, as part of attempts to ethnic cleansing.
11th September » George Stibitz performs the first remote operation of a computer.
12th September » Cave paintings are discovered in Lascaux, France.
12th September » An explosion at the Hercules Powder Company plant in Succasunna-Kenvil, New Jersey called Kenvil, New Jersey kills 51 people and injures over 200.
14th September » Ip massacre: The Hungarian Army, supported by Hungarians in Romania known as local Hungarians, kill 158 Romanian civilians in Ip, Sălaj, a village in Northern Transylvania, an act of ethnic cleansing.
15th September » World War II: The climax of the Battle of Britain, when the Royal Air Force shoots down large numbers of Luftwaffe aircraft.
16th September » World War II: Kingdom of Italy named Italian troops Italian invasion of Egypt named conquer Sidi Barrani.
17th September » World War II: Following the Nazi Germany or German defeat in the Battle of Britain, Adolf Hitler called Hitler postpones Operation Sea Lion indefinitely.
18th September » The British liner SS named City of Benares is sunk by German submarine U-48 (1939) or German submarine U-48; those killed include 77 child refugees.
19th September » Witold Pilecki is voluntarily captured and sent to Auschwitz in order to smuggle out information and start a Jewish resistance under Nazi rule In concentration camps e.g resistance.
27th September » World War II: The Tripartite Pact is signed in Berlin by Germany, Japan and Italy.
29th September » Two Avro Ansons of No. 2 Service Flying Training School RAAF 1940 Brocklesby mid-air collision known as collide in mid-air over Brocklesby, New South Wales, Australia, remain locked together after colliding, and then land safely.
1st October » The Pennsylvania Turnpike, often considered the first superhighway in the United States, opens to traffic.
4th October » Meeting between Adolf Hitler and Benito Mussolini at the Brenner Pass.
7th October » World War II: the McCollum memo proposes bringing the United States into the war in Europe by provoking the Japanese to attack the United States.
14th October » Balham tube station World War II named Balham underground station disaster in London, England, occurs during the Nazi Luftwaffe The Blitz called air raids on Great Britain.
15th October » The President of Catalonia, Lluís Companys, is executed by the Spanish dictatorship of Francisco Franco, making him the only European president to have been executed.
16th October » The Holocaust e.g Holocaust: The Warsaw Ghetto is established.
21st October » The first edition of the Ernest Hemingway novel 'For Whom the Bell Tolls' is published.
25th October » Benjamin O. Davis, Sr. is named the first African American general in the United States Army.
26th October » The P-51 Mustang makes its maiden flight.
31st October » World War II: The Battle of Britain ends the United Kingdom prevents a possible Nazi Germany e.g German invasion.
2nd November » World War II: First day of Battle of Elaia–Kalamas between the Greeks and the Italians.
5th November » World War II: The British Armed Merchantmen Armed Merchant Cruiser, HMS Jervis Bay HMS 'Jervis Bay', is sunk by the Germany German pocket battleship ship German pocket battleship Admiral Scheer 2.
8th November » Greco-Italian War: The Italian invasion of Greece fails as outnumbered Greek units repulse the Italians in the Battle of Elaia–Kalamas.
9th November » Warsaw is awarded the Virtuti Militari.
10th November » The 1940 Vrancea earthquake strikes Romania killing an estimated 1,000 and injuring approximately 4,000 more.
11th November » World War II: Battle of Taranto The Royal Navy launches the first aircraft carrier strike in history, on the Italy e.g Italian fleet at Taranto.
11th November » The Nazi Germany German cruiser 'German auxiliary cruiser Atlantis Atlantis' captures top secret United Kingdom British mail, and sends it to Japan.
11th November » Armistice Day Blizzard: An unexpected blizzard kills 144 in the U.S. Midwest.
12th November » World War II: The Battle of Gabon ends as Free French Forces take Libreville, Gabon, and all of French Equatorial Africa from Vichy France or Vichy French forces.
12th November » World War II: Soviet Foreign Minister Vyacheslav Molotov arrives in Berlin to discuss German–Soviet Axis talks named the possibility of the Soviet Union joining the Axis Powers.
14th November » World War II: In England, Coventry Blitz called Coventry is heavily bombed by German Luftwaffe bombers. Coventry Cathedral is almost completely destroyed.
16th November » World War II: In response to the Coventry Blitz or leveling of Coventry by the German Luftwaffe two days before, the Royal Air Force bombs Hamburg.
16th November » The Holocaust or Holocaust: In occupied Poland, the Nazism called Nazis close off the Warsaw Ghetto from the outside world.
20th November » World War II: Kingdom of Hungary named Hungary becomes a signatory of the Tripartite Pact, officially joining the Axis Powers Hungary e.g Axis Powers.
22nd November » World War II: Following the initial Greco-Italian War Italian invasion, Kingdom of Greece Greek troops counterattack into Albanian Kingdom (1939–1943) Italian-occupied Albania and capture Korçë Korytsa.
23rd November » World War II: Kingdom of Romania called Romania becomes a signatory of the Tripartite Pact, officially joining the Axis Powers Romania or Axis Powers.
24th November » World War II: The Slovak Republic (1939–45) or First Slovak Republic becomes a signatory to the Tripartite Pact, officially joining the Axis powers Slovakia (Tiso regime) e.g Axis powers.
25th November » World War II: First flight of the de Havilland Mosquito and Martin B-26 Marauder.
27th November » World War II: At the Battle of Cape Spartivento, the Royal Navy engages the Regia Marina in the Mediterranean Sea.
30th November » Lucille Ball marries Desi Arnaz in Greenwich, Connecticut.
12th December » World War II: Approximately Fitzalan Square The Marples tragedy called 70 people are killed in the Marples Hotel, Fitzalan Square, Sheffield, as a result of a Sheffield Blitz named German air raid.
22nd December » World War II: Himarë is captured by the Greece called Greek army.
23rd December » World War II: Greek submarine Papanikolis (Y-2) sinks the Italian motor ship 'Antonietta'.
29th December » World War II: In the Second Great Fire of London, the Luftwaffe fire-bombs London called London, England, UK, killing almost 200 civilians.