What event is considered the immediate spark that started World War I?

• A. The invasion of Belgium by Germany.
• B. The sinking of the Lusitania.
• C. The assassination of Archduke Franz Ferdinand of Austria-Hungary in Sarajevo.
• D. The Zimmerman Telegram.

Answer: (C)

The event that directly triggered the start of World War I was the assassination of Archduke Franz Ferdinand of Austria-Hungary in Sarajevo. When he was killed, Austria-Hungary saw a chance to act against Serbia, which it blamed for the murder, and issued an ultimatum. Serbia’s response fell short of what Austria-Hungary demanded, leading to Austria-Hungary declaring war. Because Europe was sewn together with alliances and mobilization plans, this local crisis spiraled quickly: Russia moved to support Serbia, Germany backed Austria-Hungary, and France and Britain became involved, pulling in more nations and turning a regional incident into a continental war. The invasion of Belgium, the Lusitania sinking, and the Zimmerman Telegram are important later events, but they did not start the fighting in 1914.