What's the process that was associated with the event that triggered world war

1

Assassination of Archduke Franz Ferdinand was the event that led to the triggering of the world war 1.

Explanation:

Archduke Franz Ferdinand who was from Austria and his wife whose name was Sophia were shot dead by a Serb nationalist group which was known as the Black hand when they had come to visit the Bosnian capital. With this assassination in Bosnia, there were a series of events that started off and led to the starting of the world war 1 in early August.