1: The Republic of China and the Empire of Japan are involved in the early stages of the third year of armed conflict between them during the Second Sino-Japanese War. The war is in what will be known as the "Second Period." The "Second Period" starts in October 1938 and ends in December 1941. This conflict would eventually be swept up into WWII when Japan joins the Axis and China the Allies.
1: The Invasion of Poland by Nazi Germany begins at 4:45 a.m. with the Luftwaffe attacking several targets in Poland. The Luftwaffe launches air attacks against Kraków, Łódź, and Warsaw. Within five minutes of the Luftwaffe attacks, the German Navy (Kriegsmarine) orders the old Battleship Schleswig-Holstein to open fire on the Polish military transit depot at Westerplatte in the Free City of Danzig on the Baltic Sea, but the attack was repulsed. By 8:00 a.m., troops of the German Army (Wehrmacht Heer), still without a formal declaration of war issued, launch an attack near the Polish town of Mokra.
1: Estonia, Finland, Latvia, Lithuania, Norway, and Switzerland declare their neutrality.
1: The British government declares general mobilization of the British Armed Forces and begins evacuation plans in preparation of German air attacks.
2: The United Kingdom and France issue a joint ultimatum to Germany, requiring German troops to evacuate Polish territory; Italian dictator Benito Mussolini declares the neutrality of his nation; President Douglas Hyde of the Republic of Ireland declares the neutrality of his nation; the Swiss government orders a general mobilization of its forces.
2: The National Service (Armed Forces) Act 1939 was enacted immediately and enforced full conscription on all males between 18 and 41 resident in the UK.
2: The Free City of Danzig is annexed by Germany.
3: At 11:15 a.m. British Standard Time (BST), British Prime Minister Neville Chamberlain announces on BBC Radio that the deadline of the final British ultimatum for the withdrawal of German troops from Poland expired at 11:00am and that "consequently this nation is at war with Germany". Australia, India, and New Zealand also declare war on Germany within hours of Britain's declaration.
3: At 12:30pm BST the French Government delivers a similar final ultimatum; which expires at 3:00pm BST.
3: Within hours of the British declaration of War, SS Athenia, a British cruise ship en route from Glasgow, Scotland to Montreal, Canada is torpedoed by the German submarine U-30 250 miles Northwest of Ireland. 112 passengers and crew members are killed. The "Battle of the Atlantic" begins.
4: At 8:00 a.m. Newfoundland Standard Time (NST), Dominion of Newfoundland declares war on Germany.
4: In the first British offensive action of the War, the Royal Air Force launch a raid on the German fleet in the Heligoland Bight. They target the German pocket-battleship Admiral Scheer anchored off Wilhelmshaven at the western end of the Kiel Canal. Several aircraft are lost in the attack and, although the German vessel is hit three times, all of the bombs fail to explode.
4: Japan announces its neutrality in the European situation. The British Admiralty announced the beginning of a naval blockade on Germany, one of a range of measures by which they waged economic warfare on the Axis Powers
4: The USA launches the Neutrality Patrol.
5: South African Prime Minister Barry Hertzog fails to gain support for a declaration of South African neutrality and is deposed by a party caucus for Deputy Prime Minister Jan Smuts.
5: The USA publicly declared neutrality.
6: South Africa, now under Prime Minister Jan Smuts, declares war on Germany.
6: Battle of Barking Creek (a friendly fire incident resulting in the first RAF fighter pilot fatalities of the War).
6: One of Germany's land forces (Wehrmacht Heer) captures Kraków in the south of Poland; Polish army is in general retreat.
7: France begins a token offensive, moving into German territory near Saarbrücken.
7: The National Registration Act 1939 is passed in Britain introducing identity cards and allowing the government to control labour.
8: The British Government announces the re-introduction of the convoy system for merchant ships and a full-scale blockade on German shipping.
9: The French Saar Offensive stalls at the heavily mined Warndt Forest having advanced approximately 8 miles into lightly defended German territory.
10: Canada declares war on Germany.
11: Viceroy of India Lord Linlithgow announces to the two houses of the Indian Legislature (the Council of State and the Legislative Assembly) that due to India's participation in the war, the plans for the Federation of India under the Government of India Act 1935 will be indefinitely postponed.
12: General Gamelin orders a halt to the French advance into Germany.
15: The Polish Army was ordered to hold out at the Romanian border until the Allies arrived.
16: The German Army complete the encirclement of Warsaw.
16: The French complete their retreat from Germany, ending the Saar Offensive
17: The Soviet Union invades Poland from the east, occupying the territory east of the Curzon line as well as Białystok and Eastern Galicia.
17: Aircraft carrier HMS Courageous torpedoed and sunk by U-29 on patrol off the coast of Ireland
17: The Imperial Japanese Army launched the attacks on the Chinese city of Changsha, when their forces in northern Jiangxi attacked westward toward Henan.
18: Polish President Ignacy Mościcki and Commander-in-Chief Edward Rydz-Śmigły leave Poland for Romania, where they are both interned; Russian forces reach Vilnius and Brest-Litovsk. Polish submarine escapes from Tallinn - Estonia's neutrality is questioned by the Soviet Union and Germany.
19: The German and Soviet armies link up near Brest Litovsk.
19: Soviet Union blockades the harbour of Tallinn, the capital of Estonia.
19: Soviet Union and its ally Mongolia wins the Battle of Khalkhin Gol against Japan, ending the Soviet-Japanese Border Wars.
19: The Japanese Imperial Army attacks the Chinese National Revolutionary Army along the Sinchiang River using poison gas during the Battle of Changsha.
20: German submarine U-27 is sunk with depth charges from the British destroyers HMS Fortune and HMS Forester.
21: Romanian Prime Minister Armand Călinescu is assassinated by the Iron Guard, an ultra-nationalistic group in Romania.
23: The Imperial Japanese Army drove the Chinese National Revolutionary Army out of the Sinchiang river area, and the 6th and 13th Divisions crossed the river under artillery cover and advanced further south along the Miluo River during the Battle of Changsha.
24: Soviet air force violates Estonian airspace. The Estonians negotiate with Molotov in Moscow. Molotov warns the Estonians that if the Soviet Union doesn't get military bases in Estonia, it will be forced to use "more radical actions".
25: German home front measures begin with food rationing.
25: Soviet air activity in Estonia. Soviet troops along the Estonian border include 600 tanks and 600 aircraft and 160 000 men.
26: Following a massive artillery bombardment, the Germans launch a major infantry assault on the centre of Warsaw.
26: Russian bombers seen in the Tallinn sky.
27: In the first offensive operations by the German Army in Western Europe, guns on the Siegfried Line open up on villages behind French Maginot line.
28: German-Soviet Boundary and Friendship Treaty is signed by Molotov and Ribbentrop. The secret protocol specifies the details of partition of Poland originally defined in Molotov-Ribbentrop Pact (August 23, 1939) and adds Lithuania to the Soviet Union sphere of interest.
28: The remaining Polish army and militia in the centre of Warsaw capitulate to the Germans.
28: Soviet troops mass by the Latvian border. Latvian air space violated.
28: Estonia signs a 10-year Mutual Assistance Pact with the Soviet Union, which allows the Soviets to have 30 000-men military bases in Estonia. As a gift in return Stalin promises to respect Estonian independence.
29: The Japanese Imperial Army reached the outskirts of Changsha. However, they were unable to conquer the city because their supply lines were cut off by the chinese National Revolutionary Army.
30: The German pocket-battleship Admiral Graf Spee sinks its first merchant ship, the British freighter Clement while off the coast of Pernambuco, Brazil.
30: French forces on the French-German border fell back to the Maginot Line in anticipation of a German invasion.
 October 19392: Latvian representatives negotiate with Stalin and Molotov. Soviets threaten an occupation by force if they do not get military bases in Latvia.
2: Declaration of Panama is approved by American Republics. Belligerent activities should not take place within waters adjacent to the American continent. A neutrality zone of some 300 miles in breadth is to be patrolled by the U.S. Navy.
3: British forces move to the Belgian border, anticipating a German invasion of the West.
3: Lithuanians meet Stalin and Molotov in Moscow. Stalin offers Lithuania the city of Vilnius (in Poland) in return for allowing Soviet military bases in Lithuania. The Lithuanians are reluctant.
5: Latvia signs a 10-year Mutual Assistance Pact with the Soviet Union, which allows the Soviets to have 25,000 men in military bases in Latvia. Stalin promises to respect Latvian independence.
6: Chinese army reportedly defeats the Japanese at the Battle of Changsha.
6: Polish resistance in the Polish September Campaign comes to an end. Hitler speaks before the Reichstag, declaring a desire for a conference with Britain and France to restore peace.
7: Lithuanians again meet the Soviets in Moscow. The Soviets demand military bases.
9: Hitler issues orders (Case Yellow) to prepare for the invasion of Belgium, France, Luxembourg, and the Netherlands.
10: The last of Poland's military surrenders to the Germans.
10: The leaders of the German navy suggest to Hitler they need to occupy Norway.
10: British Prime Minister Chamberlain declines Hitler's offer of peace.
10: Lithuania signs a 15-year Mutual Assistance Pact with the Soviet Union, which allows the Soviets to have 20,000 men in military bases in Lithuania. In a secret protocol, Vilnius is made Lithuanian territory.
11: An estimated 158,000 British troops are now in France.
12: Adolf Eichmann begins deporting Jews from Austria and Czechoslovakia into Poland.
12: French Premier Édouard Daladier declines Hitler's offer of peace.
12: Finland's representatives meet Stalin and Molotov in Moscow. Soviet Union demands Finland gives up a military base near Helsinki and exchange some Soviet and Finnish territories to protect Leningrad against Great Britain or the eventual future threat of Germany.
14: The British battleship HMS Royal Oak is sunk in Scapa Flow harbour by U-47, under the command of Günther Prien.
14: Finns meet Stalin again. Stalin tells that "an accident" might happen between Finnish and Soviet troops, if the negotiations last too long.
16: First air attack on Great Britain, aimed at ships in the Firth of Forth, Scotland.
18: First Soviet forces enter Estonia. During the Umsiedlung, 12,600 Baltic Germans leave Estonia.
19: Portions of Poland are formally inducted into Germany; the first Jewish ghetto is established at Lublin
20: The "Phoney War": French troops settle in the Maginot line's dormitories and tunnels; the British build new fortifications along the "gap" between the Maginot line and the Channel.
20: Pope Pius XII's first encyclical condemns racism and dictatorships.
27: Belgium announces that it is neutral in the present conflict.
30: The British government releases a report on concentration camps being built in Europe for Jews and anti-Nazis.
31: As Germany plans for an attack on France, German Lieutenant-General Erich von Manstein proposes that Germany attack through the Ardennes rather than through Belgium - the expected attack route.
 November 19391: Parts of Poland, including the Danzig Corridor, are annexed by Germany. Soviet Union annexes the eastern parts of occupied Poland to Ukraine and Belorussia.
3: Finland and Soviet Union again negotiate new borders. Finns mistrust Stalin's aims and refuse to give up territory breaking their defensive line.
4: The U.S. Neutrality Act is passed: the French and British may buy arms, but on a strictly cash basis. American isolationists find the act an "outrage."
4: A German physicist working at Siemens AG sends an anonymous letter to the British Embassy in Oslo offering England a report on present and future German weapons technologies.
8: Hitler escapes a bomb blast in a Munich beerhall, where he was speaking on the anniversary of the Beer Hall Putsch of 1923. British bombers coincidentally bomb Munich.
13: Negotiations between Finland and Soviet Union break down. Finns doubt that Germans and Russians have agreed to include Finland in the Soviet sphere of influence.
14: The Polish government-in-exile moves to London.
16: The first British civilian casualty occurs when a German bomber kills James Isbister in an air raid on Orkney in Scotland.
17: The IRA is blamed for bombs set off in London.
20: The Luftwaffe and German U-boats begin mining the Thames estuary.
23: Polish Jews are ordered to wear Star of David armbands.
24: Japan announces the capture of Nanning in southern China.
26: The Soviets stage the shelling of Mainila, Soviet artillery shells a field near the Finnish border, accusing Finns of killing Soviet troops.
29: The USSR breaks off diplomatic relations with Finland.
30: The Soviet Union attacks Finland in what would become known as the Winter War.
 December 19391: Russia continues its war against Finland; Helsinki is bombed. In the first two weeks of the month, the Finns retreat to the Mannerheim line, an outmoded defensive line just inside the southern border with Russia.
2: British conscription is increased to cover men from 19 to 41.
5: The Russian invaders start heavy attacks on the Mannerheim line.
7: Italy again declares its neutrality. Norway, Sweden, and Denmark also proclaim their neutrality in the Russo-Finnish quarrel.
11: The Russians meet with several tactical defeats by the Finnish army.
12: The destroyer HMS Duchess sinks after a collision with the battleship HMS Barham off the coast of Scotland with the loss of 124 men.
13: The Battle of the River Plate off Montevideo, Uruguay. A British naval squadron attacks the Admiral Graf Spee
14: The Graf Spee retreats, badly damaged, into Montevideo harbor.
14: The USSR is expelled from the League of Nations in response to the Soviet invasion of Finland on November 30.
15: Soviet Army assaulted Taipale, Finland.
17: The Graf Spee is forced by International Law to leave Montevideo harbor; it is scuttled just outside the harbor. Its captain, Hans Langsdorff, is interned.
18: The first Canadian troops arrive in Europe.
18: Germany defeats Britain in the Battle of the Heligoland Bight
20: Captain Hans Langsdorff commits *******.
27: The first Indian troops arrive in France.
28: Meat rationing begins in Britain.
29: As the year ends, the Finns continue to have successes in fighting the invaders, along the way capturing many men and vehicles.