World War I began after the Archduke( Franz Ferdinand) of the decaying Austro-Hungarian empire was assassinated in Sarajevo on June 28, 1914 by a group of Serbian nationalists. This event began the struggle between Serbia and the Austro-Hungarian government.
On 28 June 1914, the Archduke Franz-Ferdinand, wearing his seven lucky charm and his light-blue cavalry dress with bullet proof, and his wife visited Sarajevo, the capital of Bosnia, to review these troops.
It was a sunny Sunday morning. Franz Ferdinand and his wife arrive at Sarajevo railway station at 9:30 a.m. The Duke and his wife get into a dark green, open-topped car because its their wedding anniversary. It is the second car in a line of six outside the station. There were seven terrorists who came from Serbia. The main reason why did they come there was that, the only one objective, to kill the Duke, Franz Ferdinand. The first two terrorists are on Appel Quay near the station. When the cars drive past they take fright and do nothing. The third terrorist, Nedjelko Cabrinovic, is on Cumurja Bridge along Appel Quay. He throws a bomb which land under the third car injuring the passengers and driver. Just right after that incident, the one who threw the grenade, he tried to commit suicide by drinking cyanide and then jumped into the river, but he didn't die due to the fact that the river was not that too deep. The remaining five cars drive quickly to the town hall but the man in the town hall didn't know what happened. Afterwards, Gavrilo Princip bought a sandwich in Franz Joseph Street because he got hungry. The other three terrorists were waiting in the main road. At the town hall it is decided that Sophia and the Duke will return to the station by a different route. The driver is not told so the driver took a wrong turning up in Franz Joseph Street and the gear was suddenly broke down. At this moment the fourth terrorist, Princip, who is standing nearby, shoots and kills the Duke in his neck and his wife, Sophia in her stomach with a baby. Princip quickly drink the cyanide and try to shoot himself but the police was quickly to arrested him. He is later beaten up in jail.
The arrest of a member of the 'Black Hand' group after the assassination of Franz Ferdinand.
After 6 weeks, Austro-Hungary declared war on Serbia, Germany declared war on Russia (who had allied with Serbia). Two days later, Germany declared war on France and swept its armies through Belgium, violating its neutrality. Because of this, Great Britain (England, Scotland, Wales & Northern Ireland) declared war on Germany. Austro-Hungary declared war on England. And thus started WWI.