The Sarajevo Incident (June 28, 1914)
The incident took place in Sarajevo, the capital of Bosnia, which was then part of the Austro-Hungarian Empire.
The immediate cause of the First World War was the assassination of Archduke Franz Ferdinand of Austria-Hungary and his wife, Sophie Chotek, in Sarajevo on June 28, 1914, by Gavrilo Princip, a 19-year-old Serbian nationalist.
The Motivation: Princip was a member of The Black Hand, a secret society that wanted to liberate South Slavs from Austrian rule and unite them into a "Greater Serbia."