THE WORLD ATLAS

War · 1 September 1939 – 2 September 1945

Second World War

The Second World War began when Nazi Germany invaded Poland on 1 September 1939 and Britain and France declared war; Japan had been at war with China since July 1937. Germany, with the Soviet Union bound to it by a non-aggression pact, overran Poland, Denmark, Norway, the Low Countries and France by June 1940, when Italy joined it.

The Tripartite Pact of September 1940 tied Germany, Italy and Japan together as the Axis, later joined by Hungary, Romania, Bulgaria and others. Germany's invasion of the Soviet Union in June 1941 and Japan's attack on Pearl Harbor in December 1941 brought the Soviet Union and the United States into the Allied coalition alongside Britain, China and the exiled governments. After turning points at Midway, Guadalcanal and Stalingrad, the Allies invaded Italy and France while the Red Army advanced from the east. Germany surrendered on 8 May 1945. Japan, after the atomic bombings and the Soviet declaration of war, announced its surrender on 15 August and signed it on 2 September 1945.

Watch the war on the map

Dates
1 September 1939 – 2 September 1945
Casualties
An estimated 60 million to more than 75 million people died, most of them civilians, including about six million Jews murdered in the Holocaust.

The sides

Allies

Axis

Vichy France (collaborationist, officially neutral)

Timeline of the Second World War

  1. Germany invades Poland

    In August 1939 Germany and the Soviet Union signed a non-aggression pact that secretly divided eastern Europe between them. On 1 September German forces invaded Poland from the west, north and south, using massed armour and air power. Poland's army fought for over a month, but Warsaw surrendered in late September and the last Polish units in early October, and Poland was partitioned.

  2. Britain and France declare war on Germany

    Britain and France had guaranteed Poland's independence, and when Germany ignored their demand to withdraw they declared war on 3 September 1939. Australia, New Zealand, South Africa and Canada followed within days, and India was committed by its viceroy. Little fighting followed in the West for months, the so-called Phoney War, while the war at sea began at once, with U-boats attacking Allied shipping in the Atlantic.

  3. The Soviet Union invades eastern Poland

    Under the secret terms of its pact with Germany, the Soviet Union invaded Poland from the east on 17 September 1939, and the two powers divided the country. The Soviet Union went on to force bases on the Baltic states, invade Finland in November 1939 in the Winter War, and annex the Baltic states and parts of Romania in 1940, though it stayed formally neutral in the wider war.

  4. Germany invades Denmark and Norway

    Germany wanted Norway's ports for its navy and U-boats and to protect iron-ore shipments from Sweden through Narvik. On 9 April 1940 it invaded Denmark, which capitulated within hours, and Norway, where British, French and Polish troops landed to help. The Allies withdrew in early June as France collapsed, and the Norwegian army on the mainland surrendered on 10 June; Norway's king and government went into exile in London.

  5. Germany attacks France and the Low Countries

    On 10 May 1940 Germany invaded the Netherlands, Belgium and Luxembourg. Its main armoured thrust came through the Ardennes, crossing the Meuse at Sedan and racing to the Channel, cutting off the Allied armies in Belgium. The Netherlands surrendered within days and Belgium at the end of May, while more than 340,000 Allied troops were evacuated from Dunkirk by early June.

  6. Italy declares war on Britain and France

    Mussolini's Italy, allied to Germany by the Pact of Steel in 1939, stayed out of the fighting until France was clearly beaten. On 10 June 1940 Italy declared war on Britain and France and attacked in the Alps. Italy's entry spread the war to the Mediterranean, North Africa and East Africa, where Italian colonies bordered British-held Egypt, Sudan and Kenya.

  7. France signs an armistice; the Vichy regime follows

    With Paris taken on 14 June, Marshal Philippe Pétain's new government sought terms. The armistice was signed on 22 June in the forest of Compiègne, in the carriage used in 1918. Germany occupied the north and the Atlantic coast, while a French government based at Vichy ran the rest and the colonies. In London, General Charles de Gaulle called on the French to keep fighting, founding Free France.

  8. The Battle of Britain begins

    Germany needed control of the air before it could invade Britain. From 10 July to 31 October 1940 the Luftwaffe attacked shipping, airfields and then cities, but the Royal Air Force, aided by radar, was not defeated. Hitler postponed the planned invasion indefinitely. It was Germany's first major defeat of the war. Night bombing of British cities, the Blitz, continued from September 1940 until May 1941.

  9. Germany, Italy and Japan sign the Tripartite Pact

    On 27 September 1940 Germany, Italy and Japan signed the Tripartite Pact in Berlin, pledging to support each other against any new enemy, a warning aimed at the United States. Hungary, Romania and Slovakia joined in November 1940, Bulgaria in March 1941, and Croatia after its creation. Thailand allied with Japan in December 1941 and declared war on Britain and the United States in January 1942.

  10. Axis invasion of Yugoslavia and Greece

    Italy had invaded Greece in October 1940 but was driven back into Albania, and British troops arrived to help Greece. On 6 April 1941 Germany, with Italian and Hungarian forces, invaded Yugoslavia, whose government had just been overthrown for joining the Axis, and Greece. Both were conquered within weeks, Crete fell in May, and Yugoslavia was carved up, including a new Axis-aligned Independent State of Croatia.

  11. Germany invades the Soviet Union

    On 22 June 1941 Germany and its allies, including Romania, Finland and Hungary, launched Operation Barbarossa, a vast invasion along a front from the Baltic to the Black Sea. Huge Soviet armies were encircled and German forces reached the outskirts of Leningrad and Moscow by late 1941, where a Soviet counter-offensive in December pushed them back. The Soviet Union now joined Britain as an ally.

  12. Japan attacks Pearl Harbor and Western colonies in Asia

    After the United States embargoed oil exports over Japan's occupation of French Indochina, Japan struck. On 7 December 1941 its carrier aircraft attacked the US Pacific Fleet at Pearl Harbor, killing 2,403 Americans, while other forces attacked the Philippines, Guam, Wake, Malaya, Thailand and Hong Kong. The United States declared war on Japan the next day, and Germany and Italy declared war on the United States on 11 December.

  13. Nazi officials coordinate the 'Final Solution' at Wannsee

    Mass shootings of Jews by German units in the occupied Soviet Union had begun in 1941. On 20 January 1942 SS General Reinhard Heydrich convened senior officials at a villa at Wannsee in Berlin to coordinate the deportation of Europe's Jews to be killed, mostly in occupied Poland. Through killing centres such as Auschwitz-Birkenau, the Nazis and their collaborators murdered about six million Jews in the Holocaust.

  14. Singapore surrenders to Japan

    Japanese forces landed in Malaya in December 1941 and advanced rapidly down the peninsula. Singapore, Britain's main base in Asia, surrendered on 15 February 1942, and about 80,000 British, Indian, Australian and local troops became prisoners. Churchill called it the worst disaster in British military history. By May Japan had also taken the Dutch East Indies, the Philippines and most of Burma.

  15. The US Navy defeats Japan at Midway

    Japan tried to draw the remaining US carriers into a decisive battle by attacking Midway atoll. Forewarned by codebreakers, US aircraft sank all four Japanese fleet carriers in the attacking force, Akagi, Kaga, Sōryū and Hiryū, between 4 and 7 June 1942, for the loss of the carrier Yorktown. Japan could not replace the ships and trained aircrew, and the battle is widely seen as a turning point in the Pacific.

  16. US Marines land on Guadalcanal

    Japan was building an airfield on Guadalcanal in the Solomon Islands that threatened links between the United States and Australia. US Marines landed on 7 August 1942 in the first major Allied land offensive against Japan. Months of fighting on land, at sea and in the air followed, until Japan evacuated its last troops on 9 February 1943, ceding the initiative in the Pacific to the Allies.

  17. Allied landings in Vichy North Africa (Operation Torch)

    Days after the British victory at El Alamein in Egypt, American and British forces landed in Vichy-ruled Morocco and Algeria on 8 November 1942. After brief fighting, Admiral Darlan ordered French forces to stop on 10 November, and French North Africa went over to the Allies. Germany responded by occupying the rest of France on 11 November. Axis forces in Tunisia surrendered by 13 May 1943.

  18. The German Sixth Army surrenders at Stalingrad

    German forces had attacked Stalingrad on the Volga in the summer of 1942 and nearly taken the city by November. On 19 November the Red Army counter-attacked against the Romanian armies on the flanks and encircled the German Sixth Army. Its commander, Friedrich Paulus, surrendered on 2 February 1943, and about 235,000 Axis soldiers were captured. The Soviet Union kept the initiative on the Eastern Front for the rest of the war.

  19. The Battle of Kursk

    Germany's last major offensive in the East began on 5 July 1943, when its armies attacked the Soviet salient around Kursk from north and south. Soviet forces had prepared deep defences and held, and on 12 July they launched their own counter-offensive. Kursk, which included some of the largest tank battles of the war, ended Germany's ability to mount strategic offensives on the Eastern Front.

  20. Allied invasion of Sicily; Italy changes sides

    After victory in North Africa, the Allies invaded Sicily on 9 July 1943. Mussolini was deposed on 25 July, and the new Italian government signed an armistice, announced on 8 September, as the Allies landed on the mainland. Germany occupied most of Italy, freed Mussolini and set up a puppet state in the north, while the royal government joined the Allies as a co-belligerent.

  21. D-Day: the Allied landings in Normandy

    After years of preparation, Allied forces landed on five Normandy beaches, Utah, Omaha, Gold, Juno and Sword, on 6 June 1944, preceded by airborne drops. More than 156,000 soldiers came ashore on the first day in the largest seaborne invasion in history, carried by about 5,000 ships. After weeks of hard fighting the Allies broke out in late July and advanced across France.

  22. Operation Bagration destroys German Army Group Centre

    Three years to the day after the German invasion, the Red Army launched a massive offensive in Belarus on 22 June 1944. Army Group Centre's front collapsed, Minsk was liberated on 4 July, and by August Soviet forces had reached the Vistula near Warsaw and the border of East Prussia. With about 450,000 German casualties, it was among the heaviest German defeats of the war.

  23. Paris is liberated; Romania leaves the Axis

    As Allied armies broke out of Normandy and landed in southern France, the French Resistance rose in Paris, and French and American troops entered the city on 25 August 1944. Two days earlier a coup in Romania had taken it out of the Axis, and Bulgaria followed in September. Romania's oilfields were lost to Germany, and by the autumn it was losing allies and territory on every front.

  24. The Battle of Leyte Gulf

    US forces landed on Leyte in the Philippines on 20 October 1944. Japan sent almost its whole remaining fleet to attack the landings, and from 23 to 26 October the largest naval battle of the war was fought around the islands. The Japanese navy suffered crippling losses and never again sailed in comparable force. The battle also saw the first organised kamikaze attacks.

  25. Germany's Ardennes offensive: the Battle of the Bulge

    With the Allies nearing Germany's western border, Hitler gambled on a surprise winter offensive through the Ardennes on 16 December 1944, aiming to split the Allied armies and retake Antwerp. German forces made a deep bulge in the American line but were held at key points such as Bastogne, and the offensive was repulsed by mid-January 1945, using up Germany's last reserves in the West.

  26. US forces invade Okinawa

    The Allies needed bases close to Japan for the planned invasion. US forces landed on Okinawa on 1 April 1945 and fought until organised resistance ended on 22 June, under waves of kamikaze attacks at sea. About 94,000 Japanese soldiers and some 12,500 Americans died, and estimates of Okinawan civilian deaths range from 40,000 to 150,000, foreshadowing the cost of invading Japan itself.

  27. Germany surrenders unconditionally

    Soviet forces stormed Berlin in late April 1945 while American and British armies advanced from the west; Hitler killed himself on 30 April. German commanders signed an unconditional surrender at Reims on 7 May and a definitive act in Berlin-Karlshorst, which took effect at 23:01 on 8 May. The Western Allies celebrate Victory in Europe Day on 8 May, while Russia marks Victory Day on 9 May.

  28. The United States drops an atomic bomb on Hiroshima

    Japan rejected the Allied demand for unconditional surrender issued at Potsdam in July. On 6 August 1945 a US bomber dropped an atomic bomb on Hiroshima, and a second destroyed much of Nagasaki on 9 August. Estimates of deaths by the end of 1945 are 90,000–166,000 in Hiroshima and 60,000–80,000 in Nagasaki. Historians still debate whether the bombings were justified.

  29. The Soviet Union invades Japanese-held Manchuria

    At Yalta in February 1945 Stalin had agreed to join the war against Japan within about three months of Germany's defeat. The Soviet Union declared war on 8 August and invaded Manchuria an hour later, and Mongolia joined on 10 August. Soviet forces quickly overran Manchukuo, Inner Mongolia, northern Korea, southern Sakhalin and the Kuril Islands, removing Japan's last hope of a negotiated peace.

  30. Japan signs the instrument of surrender

    After the atomic bombings and the Soviet attack, Emperor Hirohito ordered acceptance of the Allied terms, and his recorded announcement of surrender was broadcast on 15 August 1945. Japanese representatives signed the instrument of surrender aboard the USS Missouri in Tokyo Bay on 2 September 1945, ending the Second World War. Japan was occupied, and its overseas empire was dismantled.

Related

Other wars of the time

Sources