Archduke Franz Ferdinand
Archduke Franz Ferdinand (December 18, 1863 – June 28, 1914) was an Archduke of Austria, Prince Imperial of Austria, Prince Royal of Hungary and Bohemia, and from 1896 until his death, heir-presumptive to the Austro-Hungarian throne.
The assassination of he and his consort in Sarajevo by the Bosnian-Serb terrorist Gavrilo Princip precipitated an Austrian Ultimatum to Serbia (whose government agents had organised the assassination) and the subsequent declaration of war against that country. This resulted in Russia giving a "blank cheque" of support to Serbia and mobilising against Austria-Hungary, with whom they had no quarrel. France had alliances with Russia, and they became by default the Entente Powers (others would later join them). Germany stood by her thirty year old alliance with Austria-Hungary and they became the Central Powers (with others later joining them). This formed the catalyst for The Great War.