World War II: Timeline of Events

While there were smaller conflicts going on already, most historians mark the beginning of the war with the German invasion of Poland. Within days, France, Britain, Canada and others declare war on Germany. Nine months later, Fascist Italy declares war on Britain and France.

After invading Denmark and Norway in April, the Germans overrun Luxembourg, the Netherlands and Belgium before turning to France, forcing the evacuation of Allied forces at Dunkirk

Germany begins aerial assault on England, including the nighttime bombing of London, in an attempt to win air superiority and prepare for an invasion. The outnumbered British resist, aided by the first use of radar in battle, and hand Germany its first significant defeat of the war.

Even though there are treaties between the two countries, Germany invades the Soviet Union. Despite initial successes, the Russians, and the Russian winter, stop the German advance outside of their major cities and settle in to a war of attrition that was also difficult for besieged civilians.

Japan mounts a surprise attack on Pearl Harbor and other U.S. facilities in the Pacific. The United States declares war on Japan, and then on Germany and Italy after they declare war. (Japan soon quickly conquers the Philippines.)

Making a 750-mile flight from the carrier Hornet, B-25 bombers led by Lieutenant Colonel James Doolittle, strike Tokyo and other cities, bringing the war to the Japanese mainland for the first time. Carriers were designed for use by much smaller aircraft.

The naval Battle of Midway, fought mostly with carrier-based aircraft, proves to be one of the most decisive Allied victories of the Pacific war. Three Japanese aircraft carriers are destroyed.

U.S. Marines storm ashore at Guadalcanal in the first large-scale invasion of a Japanese-held island. After six months of bitter jungle fighting, the American prevail, and the battle for the Pacific islands continued.

The German effort to drive allied forces out of Egypt is smashed by the British Eighth Army at the Battle of El Alamein.

American forces invade North Africa and join a British campaign that will drive the Germans off the continent by May 12, 1943.

Surrounded German forces surrender at Stalingrad, marking a turning point of the war in Russia. Soviet forces begin an almost uninterrupted offensive against Axis forces in Eastern Europe

Allied forces invade the Italian mainland two months after landing on Sicily. Italy surrenders on Sept. 8, 1943, but German forces in Italy continue to fight, including battles at Monte Cassino and Anzio. The Allies take Rome on June 4, 1944.

In the largest military assault in history, allied forces storm ashore on France's Normandy coast. After initial heavy fighting there, the Allies clear most of France and Belgium of German forces by Aug. 15.

Soviet forces from the east begin liberating concentration camps in the summer, followed by Americans from the west. Some six million European Jews were killed in a network of labor and extermination camps built to implement Hitler's "final solution of the Jewish question."

As a follow-up to the Normandy invasion, Allied forces land on the south coast of France and begin sweeping northward.

As French and American troops close in on Paris, civilians begin bitter fighting in the capital. The German commander ignores Hitler's orders to mine public buildings, museums and bridges. He surrenders on Aug. 25.

U.S. forces land in Philippines after months of U.S. air strikes. Gen. Douglas MacArthur -- who had commanded American forces there before the Japanese invasion and who had promised to return -- leads the forces. The great naval battle in Leyte Gulf follows.

Germans launch last, desperate counteroffensive on the western front, breaking through Allied lines in Belgium and creating a "bulge" in the line while using V2 rockets to attack the Allies supply port in Antwerp. An outnumbered and surrounded American force at Bastogne holds its ground until other Allied units mount a successful counterattack.

Roosevelt, Churchill and Stalin meet at Yalta to confirm a policy of demanding unconditional surrender from Germany. The Allies plan to divide Germany into four zones. That and other decisions shape political divisions of post-war Europe.

U.S. forces land and eventually capture, at great cost, the island, which was a major air base for the Japanese, whose radar and fighters were used to intercept B-29s flying to bomb targets in Japan.

Needed for air bases for the planned invasion of the Japanese home islands, Okinawa was the scene of the last big battle in the Pacific -- the Japanese lose 103,000 men and U.S. casualties of 48,000 include 12,000 dead. U.S. naval forces offshore sustain heavy damage in suicide attacks by Japanese planes.

Conference opens in San Francisco that will formally organize the United Nations, a name coined by President Franklin Roosevelt to describe the countries fighting the Axis nations.

Italian dictator Benito Mussolini and his mistress, Clara Petacci, are caught by Italian partisans and executed after a summary court martial.

German dictator Adolf Hitler refused to leave Berlin as Russian forces entered the city. On April 29 he marries his long-time mistress, Eva Braun, in an underground shelter. The two commit suicide the next day and their bodies are burned. Berlin eventually falls to the Russians.

After years of Allied bombing, and with U.S., Soviet, British and French forces advancing daily, Germany surrenders unconditionally about a week after Hitler's death. VE Day (for Victory in Europe) is declared.

First atomic bomb dropped on Hiroshima; 130,000 killed, injured or missing. Second atomic bomb is dropped on Nagasaki three days later; 75,000 killed or wounded.

Japan surrenders unconditionally. VJ Day is declared and the Japanese formally sign surrender documents on Sept. 2 aboard the USS Missouri in Tokyo Bay.