When I was in university they taught me that the initial cause of the WWI was the assassination of the heir apparent to the throne of Austria Hungary, Franz Ferdinand. That he was his father's favorite choice, that he was a "liberal", well . . . no matter. At any rate, Gravrillo Princep was sixteen years old when he committed the heinous act of regicide. However, since Austria-Hungary was a land where there was rule of law, and, capital punishment didn't apply to minors, Gavrillo waited in his jail cell for four years years while WWI dragged on. Unfortunately for the boy, he reached majority before the Empire he dreamed would fall apart was still intact, so . . . A few months later, or maybe later, that Empire disappeared into history, and Gavrillo became a national hero of Serbia.