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
Trialism in Austria-Hungary Trialism in Austria-Hungary In the history of the Austria-Hungary trialism was the political movement that aimed to reorganize the bipartite Empire into a tripartite one, creating a Croatian state equal in status to Austria and Hungary. Franz Ferdinand promoted trialism before his assassination in 1914 to prevent the Empire from being ripped apart by Slavic dissent. The Empire would be restructured three ways instead of two, with the Slavic element given representation at the highest levels equivalent to what Austria and Hungary had at the time. Serbians saw this as a threat to their dream of a new state of