Question

What incident triggered the start of world war 1

Answer 1

Answer: The assignation of Archduke Franz Ferdinand who was killed by Surbian nationalist named Gavrilo princip.

Explanation: Hope this helps :)

Answer 2

OK so basically the main reason that had caused WWI was when the arch duke of Austria Hungary Franz Ferdinand was assassinated because the assassin had ties to a military group called the black hand so it had caused European powers to collide against each other.