Serbian Campaign of World War I Serbia, Montenegro, and Greece. When Bulgaria attacked both Serbia and Greece on 16 June 1913, it lost most of its Macedonian region to those countries, and additionally the Southern Dobruja region to Romania and Adrianople (the present-day city of Edirne) to Turkey in the 33-day Second Balkan War, which further destabilized the region. On 28 June 1914, Gavrilo Princip, a Bosnian Serb student and member of a multi-ethnic organisation of national revolutionaries called Young Bosnia, assassinated Archduke Franz Ferdinand of Austria, the heir to the Austro-Hungarian throne, in Sarajevo, Bosnia. The political objective of the assassination was the independence of
Russian entry into World War I was in agreement with President minister Raymond Poincaré who trusted him. He promised unconditional French support to Russia in the unfolding crisis with Germany and Austria. Historians debate whether he exceeded his instructions but they agree he failed to inform Paris of exactly what was happening, and did not warn that Russian mobilization might launch a world war. When on 28 June 1914 Archduke Franz Ferdinand of Austria was assassinated in Sarajevo Tsar Nicholas vacillated as to Russia's course of action. A relatively new factor influencing Russian policy was the growth of the Pan-Slavism spirit that identified Russia's duty to