World War II was a global conflict fought from 1939 to 1945 between the Allied Powers and the
Axis Powers. The war began when Invasion of Poland by Adolf Hitler's Germany prompted United
Kingdom and France to declare war. The Axis powers, led by Germany, Italy, and Japan, sought
territorial expansion and dominance, while the Allies fought to stop them.
In the early years of the war, Germany achieved rapid victories across Europe using a military
strategy known as Blitzkrieg, or "lightning war." German forces conquered much of Western
Europe, including France in 1940. Meanwhile, Japan expanded throughout Asia and the Pacific.
The conflict grew even larger in 1941 when Germany invaded the Soviet Union and Japan attacked
Attack on Pearl Harbor, bringing the United States into the war.
The tide began to turn in favor of the Allies between 1942 and 1943. Key battles such as Battle of
Stalingrad and Battle of Midway halted Axis advances and inflicted major losses. Allied industrial
strength, combined with cooperation among nations such as the United States, the Soviet Union,
and the United Kingdom, enabled large-scale military offensives that gradually pushed Axis forces
back on multiple fronts.
In 1944, the Allies launched Normandy Landings, commonly known as D-Day, opening a major
front in Western Europe. Allied armies advanced toward Germany from the west while Soviet
forces pushed from the east. Germany surrendered in May 1945 after Hitler's death, ending the war
in Europe. However, fighting continued in the Pacific as Allied forces moved closer to Japan.
The war ended in August and September 1945 after the United States dropped atomic bombs on the
cities of Hiroshima and Nagasaki. Japan formally surrendered on September 2, 1945. World War II
resulted in an estimated 60–80 million deaths, making it the deadliest conflict in human history. It
also led to major global changes, including the creation of the United Nations and the beginning of
the Cold War.