Battle of Cer On 28 June 1914, Bosnian Serb student Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria in Sarajevo. The assassination precipitated the July Crisis, which led Austria-Hungary to issue an ultimatum to Serbia on 23 July on suspicion that the assassination had been planned in Belgrade. The Austro-Hungarian government made the ultimatum intentionally unacceptable to Serbia, and it was indeed rejected. The Austro-Hungarians declared war on Serbia on 28 July and that same day the Serbs destroyed all bridges on the Sava and Danube rivers in order to prevent the Austro-Hungarians from using them during any future invasion. Belgrade was shelled
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