World War II was a global conflict that lasted from 1939 to 1945, involving many nations and resulting in significant political, social, and economic changes worldwide. The war began with the German invasion of Poland, leading to the formation of two major alliances: the Axis powers, comprising Germany, Italy, and Japan, and the Allied powers, including the United States, the Soviet Union, and the United Kingdom.

Numerous battles played crucial roles in shaping the outcome of World War II. The Battle of Stalingrad (1942-1943) marked a turning point on the Eastern Front, as the Soviet Union successfully halted the German advance, leading to a series of defeats for the Axis forces. The Battle of Midway (1942) in the Pacific was a pivotal naval engagement, where the United States dealt a significant blow to the Japanese fleet, shifting the balance of power in the Pacific theater.

The D-Day invasion (1944) was a monumental Allied operation that involved the landing of troops on the beaches of Normandy, ultimately leading to the liberation of Western Europe from Nazi control. The Battle of the Bulge (1944-1945) was a major German offensive in the Ardennes region, but the Allies successfully repelled the attack, hastening the end of the war in Europe.

Other significant battles include the Battle of Guadalcanal (1942-1943), the Battle of Kursk (1943), and the Battle of Berlin (1945). Ultimately, World War II concluded with the unconditional surrender of Germany in May 1945 and Japan in September 1945, reshaping the global order and leaving an indelible impact on history.