Hi there! I'm Asia, here to help you!
WW1 started because of the following reasons ::
militarism
alliances
nationalism
imperialism
assassination
WW1 started after a man named Archduke Franz Ferdinand (from Austria). After they murdered someone, it resulted into a war throughout the whole continent of Europe. This war lasted for 4 years (1914-1918)
Hope this helped, and i hope this is what u were looking for!
