World War I
Dates: 28 July 1914 – 11 November 1918
- Trigger: on 28 June 1914, Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, was assassinated in Sarajevo by a Serbian nationalist.
- Outbreak: on 28 July 1914, Austria-Hungary declared war on Serbia, and the conflict began.
- Main belligerents:
- Allies: Britain, France, Russia, Serbia, Italy, the United States (joined in 1917) and others.
- Central Powers: Germany, Austria-Hungary, the Ottoman Empire, Bulgaria.
- End: Germany surrendered in 1918, signing the Armistice of Compiègne on 11 November.
World War II
Dates: 1 September 1939 – 2 September 1945
- Trigger: on 1 September 1939, Nazi Germany invaded Poland.
- Outbreak: on 3 September 1939, Britain and France declared war on Germany.
- Main belligerents:
- Allies: Britain, the Soviet Union (from 1941), the United States (from 1941), China, France and others.
- Axis: Germany, Italy, Japan.
- End in Europe: 8 May 1945 (Germany’s unconditional surrender).
- End in the Pacific: 2 September 1945 (Japan signed the instrument of surrender aboard the USS Missouri).