The direct cause of World War I was the assignation of Archduke Franz Ferdinand on 28 June 1914 at Sarajevo. However, there is never one single cause of a war between the world's superpowers. There are always many different causes and the last cause is often the tipping point. In this case, it was the assignation of Archduke Franz Ferdinand. Some of the main causes were the conflict between Germany and France over Alsace, Britain and Germany over their respective naval forces, and Russia and Austria over who owns the Balkans.
