Gavrilo Princip fired the shot that started World War I when he killed Archduke Franz Ferdinand . Princip , a Slav nationalist , wanted to drive the Austro - Hungarians out of Bosnia . He was a high school student when he carried out the assassination , in Sarajevo . He got close to his victim purely by chance , and only fired one shot .
Gavrilo Princip fired the shot that started World War I when he killed Archduke Franz Ferdinand . Princip , a Slav nationalist , wanted to drive the Austro-Hungarians out of Bosnia . He was a high school student when he carried out the assassination , in Sarajevo . He got close to his victim purely by chance , and only fired one shot .