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
July Crisis July Crisis The July Crisis was a series of interrelated diplomatic and military escalations among the major powers of Europe in the summer of 1914 that was the penultimate cause of World War I. The crisis began on June 28, 1914, when Gavrilo Princip, a Bosnian Serb, assassinated Archduke Franz Ferdinand, heir presumptive to the Austro-Hungarian throne. A complex web of alliances, coupled with miscalculations by many leaders that war was in their best interests or that a general war would not occur, resulted in a general outbreak of hostilities among every major European nation in early August 1914. Austria-Hungary