World War II transformed the political, economic, and social structures of the world, and established the foundation of international relations for the rest of the 20th century and into the 21st century.

World War II, or the Second World War, was a global conflict involving all continents of the world, except Antarctica. It involved fighting in most of the world from 1939 to 1945. Some fighting started in 1937, when Imperial Japanese forces started the Second Sino-Japanese War.

The causes of World War II have been given considerable attention by historians. The immediate precipitating event was the invasion of Poland by Nazi Germany on September 1, 1939, and the subsequent declarations of war on Germany made by Britain and France , but many other prior events have been suggested as ultimate causes.

This is a timeline of events of World War II in 1939 from the start of the war on 1 September 1939. For events preceding September 1, 1939, see the timeline of events preceding World War II. Germany's invasion of Poland on 1 September 1939 brought many countries into the war. This event, and the declaration of war by France and Britain two days ...

World War II was a conflict that involved virtually every part of the world during 1939–45. The main combatants were the Axis powers (Germany, Italy, and Japan) and the Allies (France, Great Britain, the United States, the Soviet Union, and China).

Oct 29, 2009 · World War II, the largest and deadliest conflict in human history, involved more than 50 nations and was fought on land, sea and air in nearly every part of the world.

Nov 15, 2021 · World War II was the largest and most destructive conflict in history. Learn about key WWII dates in this timeline of events, including when WW2 started and ended.

May 5, 2021 · With Adolf Hitler leading a German invasion of Poland in 1939, World War II was launched, a deadly global conflict waged across Europe and the Pacific until 1945. Bloody battles raged between...