Tension had been rising between the European powers for
many years. The events that took place in Sarajevo in 1914, unleashed
a series of events that finally lighted a fuse which would explode into
the First World War. The key event, which started this chain reaction
was the assassination of the Archduke Franz Ferdinand, who was the heir
to the throne of the Austro-Hungarian Empire.hope that answered your question :) have a nice day :)