19401945

1940–1945 denotes the central years of World War II, a global conflict that pitted the Axis powers—primarily Germany, Italy, and Japan—against the Allied powers led by the United Kingdom, the Soviet Union, the United States, China, and others. The period saw widespread military campaigns across Europe, North Africa, the Mediterranean, the Atlantic, and the vast Pacific and Asian theaters, as well as profound political and social upheaval and the Holocaust.

Europe and Africa: The war widened from the 1940 Blitz and the fall of France to a protracted struggle that included the Battle of Britain (1940), the invasion of the Soviet Union (1941), and the North Africa campaigns. The Allied invasion of Normandy in 1944 opened a Western front; Soviet forces advanced from the east, culminating in the fall of Berlin in 1945. VE Day on May 8, 1945, marked the end of wartime hostilities in Europe.

Pacific and Asia: After Japan's attack on Pearl Harbor in December 1941, major campaigns continued through 1942–1945, including Midway, Guadalcanal, and island hopping toward Japan, with heavy fighting in the Philippines, Iwo Jima, and Okinawa. Japan announced surrender in August 1945 after the atomic bombings of Hiroshima and Nagasaki and the Soviet Union's declaration of war in the region; formal surrender occurred on September 2, 1945, bringing World War II to a close.

Aftermath: The conflict produced unprecedented civilian and military casualties, the Holocaust's enormity, and significant geopolitical shifts. The United Nations was established in 1945, and postwar arrangements, trials of war crimes, and the beginnings of decolonization and a bipolar world order emerged in the following years.