HistoryData
Historical ConflictGlobal (Europe, Pacific, Africa, Asia)

World War II

The deadliest conflict in history, killing up to 75 million people, it reshaped global power, ended European dominance, and founded the modern international order.

Duration & Scope

1939 1945

6 years

Estimated Total Casualties

70.0M

Key Facts

Duration
6 years (1 Sep 1939 – 2 Sep 1945)
Total deaths
60–75 million
Countries involved
Nearly all of the world's countries
Nuclear weapons used
2 atomic bombs (Hiroshima and Nagasaki, Aug 1945)
Germany's surrender
8 May 1945 (V-E Day)
Japan's surrender
2 September 1945 (V-J Day)

Strategic Narrative Overview

Germany rapidly conquered Western Europe by mid-1940, while Italy joined the Axis. Britain withstood the aerial Battle of Britain. Germany invaded the Soviet Union in June 1941, opening a massive Eastern Front. Japan's December 1941 attack on Pearl Harbor brought the United States into the war. Allied momentum turned at Stalingrad and Midway in 1942–1943. Italy fell in 1943, France was liberated after the Normandy landings in 1944, and the Axis was forced into retreat on every front.

01 / The Origins

Unresolved grievances from World War I, the rise of fascism in Europe, and Japanese militarism created mounting instability through the 1930s. Japan's 1931 invasion of Manchuria, the Second Sino-Japanese War from 1937, and Germany's annexations of Austria and the Sudetenland preceded the formal outbreak. On 1 September 1939, Nazi Germany invaded Poland; Britain and France declared war on Germany in response, drawing Europe into open conflict.

03 / The Outcome

Soviet forces captured Berlin in May 1945, and Germany surrendered unconditionally on 8 May. The United States dropped atomic bombs on Hiroshima and Nagasaki in August, prompting Japan's surrender on 2 September 1945. Germany, Austria, Japan, and Korea were occupied by Allied powers. War crimes tribunals prosecuted Axis leaders. The United Nations was established, the United States and Soviet Union emerged as rival superpowers, and European colonial empires began to collapse.

Belligerents & Mobilization Analysis

Side A

3 belligerents

Nazi GermanyImperial JapanFascist Italy
Key Commanders

Adolf Hitler, Hideki Tojo, Benito Mussolini.

Side B

3 belligerents

United StatesSoviet UnionUnited Kingdom and Commonwealth
Key Commanders

Franklin D. Roosevelt, Winston Churchill, Joseph Stalin.

Total Casualties (all sides)
70,000,000
Outcome
Allied victory; unconditional surrender of Germany (8 May 1945) and Japan (2 Sep 1945); Axis leaders tried for war crimes

Kinetic Engagement Axis

Major engagements timeline (1939–1945)Timeline of major military engagements plotted chronologically.193919451939Invasion of PolandAllied1940Battle of BritainSide B1940Battle of the At…Side B1941Attack on Pearl …Allied1943Battle of Stalin…Side B1942Battle of MidwaySide B1943Allied Invasion …Side B1943Allied Invasion …Side B1944D-Day (Normandy …Side B1945Fall of BerlinSide B1945Atomic bombing o…Side B

Scroll horizontally to view full axis. Events plotted relatively.

Side A victorySide B victoryInconclusiveDecisive / turning point