On this day, 100 years ago, the Austrian-Hungarians invaded Serbia and kicked off a war that would cost over 17 million lives.

It would change the world in almost every way. Empires would give way to new nations. New technologies would be debuted. New words would enter the lexicon.

World War I would also pave the way for the costliest conflict this world has ever seen because of the short-sightedness of the victors.