World War II

Overview

World War II was a global conflict from 1939 to 1945, involving over 50 countries and 100 million mobilized military personnel. The war became the largest conflict in human history in terms of geographic scale and human cost, with an estimated 70 million to 85  million fatalities—including over 50 million civilians.

1440 Findings

Hours of research by our editors, distilled into minutes of clarity.

  • A collection of contemporary maps from World War II

    Newspapers published detailed maps of the conflict in real-time. See different portrayals of the situation, ranging from propaganda maps to speculative maps about the war's outcome. The fascinating depictions reveal how maps can show us the aspirations and intentions of different players in a global conflict.

  • Japan was an empire from 1868 until 1947

    The Empire of Japan began on Jan. 3, 1868, and facilitated rapid modernization. It endured through a period of colonial expansion—including Korea and Taiwan—1930s militarism, and participation in WWII, until Japan’s formal transformation into a constitutional state under the 1947 constitution following Allied occupation.

  • The Nazis and Soviets agreed to a non‑aggression pact in 1939

    On August 23, 1939, Nazi Germany and the Soviet Union signed the Molotov–Ribbentrop Pact—a public commitment to not attack each other combined with a secret agreement dividing Eastern Europe into spheres of influence. This pact enabled Germany to invade Poland unopposed from the east and delayed conflict with the USSR until June 1941.

  • Germany’s invasion of Poland in 1939 launched World War II

    On September 1, 1939, Nazi Germany launched a surprise invasion of Poland using blitzkrieg—coordinated air bombardments and armored assaults—to overwhelm Polish defenses within weeks. This lightning-strike strategy shocked the world and signaled both the start of World War II and a revolutionary shift in modern military tactics.

  • The “Phoney War” was an eight‑month build-up to war

    From September 1939 to May 1940, following their war declaration on Germany, Britain and France entered a phase of military inaction—even as civil defence measures, naval blockades, and rationing intensified at home. Skirmishes were limited, but the decisive fighting didn't begin until Germany invaded Norway and France in April–May 1940, abruptly ending the uneasy stalemate.

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