The Canadian Encyclopedia — neutral, cited, updated
July 26, 2026Sources cited
Canadianwire.
Canada’s encyclopedia & explainer
Home›Politics & World›History›Seconde Guerre mondiale
Politics & World • History

Seconde Guerre mondiale

La Seconde Guerre mondiale est un conflit mondial qui s’est déroulé de 1939 à 1945.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

World War II was a global conflict that lasted from 1939 to 1945. It primarily pitted the Allies against the Axis powers, and ended with the surrender of Germany on 8 May 1945 and Japan on 2 September 1945. The war began on 1 September 1939 with the invasion of Poland by Nazi Germany.

Origins and outbreak

The war began on 1 September 1939 when Germany invaded Poland. It occurred in the context of the rise of totalitarian regimes and international tensions of the interwar period.

Course of the conflict

The conflict quickly spread to multiple continents and pitted the Allies against the Axis powers. It mobilized unprecedented military, economic, and human resources.

Mass violence and genocides

World War II was marked by extreme violence against civilians, including bombings, deportations, and the Nazi policy of extermination. The Holocaust and other mass crimes made it a war of annihilation.

End of the war and consequences

Germany surrendered on 8 May 1945 and Japan on 2 September 1945, after the atomic bombings of Hiroshima and Nagasaki. The war left Europe devastated and contributed to the creation of the United Nations as well as the division of Germany.

Key facts

  • The war began on 1 September 1939 with the invasion of Poland by Nazi Germany.
  • The conflict was fought between the Allies and the Axis powers across Europe, North Africa, Asia, and the Pacific.
  • The war caused over 60 million deaths, military and civilian.
  • It was a total war characterized by mass atrocities, including the Holocaust.
  • The war ended with the surrender of Germany on 8 May 1945 and Japan on 2 September 1945, leading to the creation of the UN and the onset of the Cold War.
🍁
Canadian context

Le Canada a participé à l’effort allié pendant la Seconde Guerre mondiale, notamment en Europe et dans l’Atlantique, ce qui en fait un événement majeur de l’histoire canadienne du XXe siècle.

Frequently asked questions

When did World War II begin?
It began on 1 September 1939 with the invasion of Poland by Nazi Germany.
When did World War II end?
It ended in Europe on 8 May 1945 and worldwide on 2 September 1945 with the surrender of Japan.
Who fought in the war?
The main camps were the Allies and the Axis powers, led respectively by coalitions around the United Kingdom, the USSR, and the United States, and by Germany, Italy, and Japan.
Why is it called a total war?
Because the conflict mobilized all state resources and heavily affected civilian populations, economies, and infrastructure.
How many deaths did the war cause?
Current estimates exceed 60 million deaths, both civilian and military.
What were the main political consequences?
The war led to the creation of the United Nations, the occupation and division of Germany, and the beginning of the Cold War.

References

  1. Ministère de l’Intérieur (France) — https://formation-civique.interieur.gouv.fr/fiches-par-thematiques/histoire-geographie-et-culture/les-conflits-mondiaux-et-le-nouvel-ordre-mondial/la-seconde-guerre-mondiale-1/
    Supports: Déclenchement de la guerre, dates de fin, capitulation allemande et japonaise, création de l’ONU
  2. Ministère de l’Intérieur (France) — https://formation-civique.interieur.gouv.fr/fiches-par-thematiques/histoire-geographie-et-culture/les-conflits-mondiaux-et-le-nouvel-ordre-mondial/les-conflits-mondiaux-la-seconde-guerre-mondiale-1939-1945-les-consequences/
    Supports: Caractère de guerre d’anéantissement, violences contre les civils, morts estimées, conséquences politiques
  3. United States Holocaust Memorial Museum — https://encyclopedia.ushmm.org/content/fr/article/world-war-ii-in-europe
    Supports: Invasion de la Pologne et déclenchement de la guerre en Europe
  4. Alloprof — https://www.alloprof.qc.ca/fr/eleves/bv/monde-contemporain/la-deuxieme-guerre-mondiale-h1099
    Supports: Capitulation du Japon le 2 septembre 1945 et fin de la guerre