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September 1, 1939
World War II begins when Nazi Germany invades Poland’s capital in a massive encirclement attack. Within weeks of the invasion, German forces defeat the Polish army and receive Warsaw’s official surrender. -
September 3, 1939
Following the attack on the Allied nation of Poland, Britain and France declare war on Germany. -
April 9, 1940
Germany invades Norway and Denmark. -
May 10, 1940
Germany launches an invasion of Belgium, the Netherlands, Luxembourg, and France. Within a few weeks, all but France have surrendered. -
June 22, 1940
France signs its official surrender to Germany. -
July 10, 1940
Germany begins its bombing raid against Great Britain in the Battle of Britain. -
September 13, 1940
Italian troops invade British-controlled Egypt in an attempt to expand Italian territories in North Africa and capture the strategically important Suez Canal. -
September 27, 1940
Germany, Italy, and Japan sign the Tripartite Pact in Berlin to formalize the alliance of the Axis Powers. The Pact provides for mutual assistance should any of its members suffer attack by any nation not already involved in the war. -
June 22, 1941
In the largest German military effort of World War II, Nazi Germany launches Operation Barbarossa, the invasion of the Soviet Union. Within a few weeks, the Soviet Union has formally joined the Allied nations. -
December 7, 1941
Japan launches a surprise attack on American soil and bombs Hawaii’s naval base at Pearl Harbor on the island of Oahu. More than 2,300 American soldiers and sailors die in the attack, and another 1,100 are wounded. -
December 8, 1941
Following the attack on Pearl Harbor, President Franklin D. Roosevelt requests, and subsequently receives, a declaration of war against Japan. With approval from Congress, the United States begins the mobilization of civilian defense groups on the home front. -
December 11, 1941
In response to the United States’ war declaration on Japan, and as part of the Axis Powers Tripartite agreement, Germany and Italy declare war on the United States. The previously neutral United States reciprocates the declarations, officially entering World War II as part of the Allied Powers. -
February 15, 1942
Japan overcomes British resistance and captures Singapore, Britain's last strategic foothold in the East. -
February 19, 1942
In a war effort against Japan, President Roosevelt signs the Executive Order 9066, also known as the Japanese-American Internment order, which calls for the capture and incarceration of all Japanese-Americans in the United States. In the months following the order, over 100,000 American citizens of Japanese descent, including children, are interned at scattered locations across the United States. -
May 12, 1942
After several months of combat with U.S. and Filipino forces, Japan captures the Philippines when the last Allied troops surrender on the island of Mindanao. -
May 26, 1942
Japan overcomes Allied efforts and completes the capture of Burma, ending British rule in the country. -
June 7, 1942
The Allies defeat Japan near the Hawaiian coast in the Battle of Midway. The battle marks a turning point in favor of the Allies. -
February 2, 1943
German troops surrender to the Soviet Red Army in Stalingrad, USSR. -
May 13, 1943
After a three year stalemate in North Africa, Axis troops surrender to Allied forces in Tunisia. -
September 8, 1943
General Dwight D. Eisenhower publicly announces Italy’s surrender to the Allies, which had been signed five days earlier in Sicily. Italy becomes the first of the Axis Powers to break and substantially weaken the Tripartite Pact. -
November 28 - December 1, 1943
President Roosevelt, British Prime Minister Winston Churchill, and Soviet Premier Joseph Stalin meet in Tehran, Iran to coordinate military strategy around the Allied invasion of German-occupied France and discuss political issues such as postwar settlements. -
June 6, 1944
Allied troops land on the beaches of Normandy, France, in a highly calculated effort to liberate Western Europe from Nazi control. The invasion, code named D-Day, becomes the largest amphibious military operation in history. -
October 26, 1944
Japan's navy is defeated by the Allies in the Battle of Leyte Gulf near the Philippines. -
December 16, 1944 - January 16, 1945
Germany launches its last major offensive campaign in the Ardennes region of Belgium and Luxembourg. The Battle of the Bulge becomes the largest battle fought along the Western Front during World War II, and the German forces are ultimately driven back by Allied troops. -
February 4–11, 1945
President Roosevelt, Prime Minister Churchill, and Premier Stalin meet in Yalta on the Crimean Peninsula. During the Yalta Conference, the leaders discuss terms for Germany’s unconditional surrender, including postwar reparations, government, and borders. Additionally, the Soviet Union agrees to join the fighting against Japan in the Pacific, following Germany’s surrender. -
March 26, 1945
After a month-long battle with Japanese forces, Allied troops capture the island of Iwo Jima in the western Pacific. -
May 7, 1945
Germany surrenders to the Allies in Reims, France, ending World War II in Europe. -
August 6, 1945
The United States drops an atomic bomb on the Japanese city of Hiroshima, becoming the first and only nation to use atomic weaponry in a wartime effort. The bomb’s immediate impact takes the lives of an estimated 60,000 to 80,000 Japanese, American, and Korean inhabitants. In the months following the explosion, the total fatalities rises to an estimated 135,000 as a direct or indirect result of the bomb. -
August 9, 1945
The United States drops an atomic bomb on the Japanese city of Nagasaki. An estimated 40,000 to 75,000 people die immediately following the explosion, while an additional 60,000 people suffer severe injuries. By the end of 1945, the total death count reaches an estimated 80,000. -
September 2, 1945
Japan formally surrenders to the Allies and signs the Japanese Instrument of Surrender in Tokyo Bay, effectively ending World War II in its entirety.
