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
Hungary in World War I to defend. Hungary in World War I At the outbreak of World War I, Hungary was part of the dualist monarchy, Austria-Hungary. Although there are no significant battles specifically connected to Hungarian regiments, the troops suffered high losses throughout the war. In 1914, Austria-Hungary was one of the great powers of Europe, with an area of 676,443 km² and a population of 52 million, of which Hungary had 325,400 km² with population of 21 million. On June 28, 1914, Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria. Before entering the war, only the prime minister Count István Tisza hesitated, unconvinced