the assassination of Archduke Francis Ferdinand.
The assassination of Archduke Franz Ferdinand of Austria, by Gavrilo Princip on June 28, 1914. On July 23, 1914, Austria set an ultimatum for Serbia to leave Austria. This ultimatum would expire on July 28, 1914. When the Serbs would still not leave, Austria declared war on Serbia.
You have not told us which event, or which revolution you are asking about.
The assasination of Archduke Franz Ferdinand
On July 31 Germany sent a 24-hour ultimatum requiring Russia to halt its mobilization and an 18-hour ultimatum requiring France to promise neutrality in the event of war between Russia and Germany.
onFocus
It wasn't directly a country that started WW1 but there wasn't a specific event that caused it either, it was just a build up of events. One of the most common and one of the biggest events that happened before WW1 was the assassination of Arch Duke Franz Ferdinand.
Many events happen in Serbia every day. Please ask a specific question.
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