Battle of Kolubara their respective commands, and the 5th and 6th armies were merged into a single 5th Army of 95,000 men. 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
Archduke Franz Ferdinand of Austria Franz Ferdinand's death, with Austria-Hungary's declaration of war against Serbia. The assassination of Ferdinand is considered the most immediate cause of World War I. Franz Ferdinand is interred with his wife Sophie in Artstetten Castle, Austria. Archduke Franz Ferdinand and his Castle of Artstetten were selected as a main motif for the Austrian 10 euro The Castle of Artstetten commemorative coin, minted on 13 October 2004. The reverse shows the entrance to the crypt of the Hohenberg family. There are two portraits below, showing Archduke Franz Ferdinand and his wife Sophie, Duchess of Hohenberg. The Scottish band Franz Ferdinand named