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
History of the Balkans war set the stage for the Balkan crisis of 1914 and thus was a "prelude to the First World War." The monumentally colossal World War I was ignited from a spark in the Balkans, when a Bosnian Serb named Gavrilo Princip assassinated the heir to the Austrian throne, Franz Ferdinand. Princip was a member of a Serbian militant group called the Crna Ruka (Serbian for "Black Hand"). Following the assassination, Austria-Hungary sent Serbia an ultimatum in July 1914 with several provisions largely designed to prevent Serbian compliance. When Serbia only partially fulfilled the terms of the ultimatum, Austria-Hungary declared war