The assassination of archduke ferdinand was one of the major causes of what?

The Assassination of Archduke Ferdinand (of Austria) was due to the hostilities that were brewing at the time. He was killed by an irredentist serb Gavrilo Princip who wanted the annexation of Bosnia since Serbs felt Bosnia. Austria was allied with Germany while Serbs were allied with Russia. Because France was allied with Russia, Britain felt that if anyone was to invade France they would easily invade Britain through the channel so they joined with Serbia, France, and Russia. Plus due to the rise of militarism and Imperialism everyone felt on the rise to conquer and was paranoid of being conquered.