Political map of Europe & the Mediterranean 28 June 1914 (Assassination of Franz Ferdinand): Serbia's sudden expansion in the Balkan Wars (Second Balkan War) increased tensions between it and Austria-Hungary, which had a significant Serb minority. On June 28, 1914, the Austro-Hungarian Archduke Franz Ferdinand (Archduke Franz Ferdinand of Austria) was assassinated (Assassination of Archduke Franz Ferdinand) by a Bosnian Serb terrorist (Gavrilo Princip) while visiting Sarajevo (Sarajevo). Austria-Hungary quickly seized upon the assassination as an excuse to crush Serbia (July Ultimatum). However, while Austria-Hungary was backed by Germany (Dual Alliance, 1879), Serbia was supported by Russia, which in turn was allied to France (Franco-Russian Alliance).