What Caused World War 1?
The Great War erupted in 1914 after decades of building tensions. One assassination lit the fuse.
Long-Term Causes
- Triple Alliance: Germany, Austria-Hungary, Italy
- Triple Entente: France, Russia, Britain
An attack on one meant war with all.
#### Imperial Rivalries
European powers competed for colonies, markets, and prestige. Germany, arriving late to imperialism, demanded its "place in the sun."
#### Nationalism
Ethnic groups sought independence or unification. In the Balkans especially, nationalist tensions simmered.
#### Militarism
Arms races (especially Germany vs. Britain in naval power) created massive standing armies and war plans ready to execute.
The Spark
June 28, 1914: Archduke Franz Ferdinand, heir to Austria-Hungary, was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist.
Austria-Hungary blamed Serbia. Russia backed Serbia. Germany backed Austria-Hungary. France backed Russia. Alliances activated like dominoes.
The July Crisis
- July 28: Austria-Hungary declared war on Serbia
- July 30: Russia mobilized
- August 1: Germany declared war on Russia
- August 3: Germany declared war on France, invaded Belgium
- August 4: Britain declared war on Germany
Within six weeks, most of Europe was at war.
The Human Cost
- 9 million soldiers dead
- 21 million wounded
- Empires collapsed (German, Austro-Hungarian, Ottoman, Russian)
- The seeds of WW2 were planted
Related Reading
Listen to the Full Course
Explore the Great War in World War 1: Complete Guide.