Young Bosnia and the Battle of Kosovo. Two notable organizations are referred to in connection with Young Bosnia: Narodna Odbrana and Black Hand. During a Serbian kangaroo court in French-occupied Salonika in 1916–17, Chief of Serbian Military Intelligence Dragutin Dimitrijević Apis testified that he had organized the assassination of Archduke Franz Ferdinand of Austria, in Sarajevo on 28 June 1914, (the assassin was Gavrilo Princip). In the process, he used not only his power over elements of the Serbian military, but also the Black Hand. Leaders of the Black Hand in turn had penetrated Narodna Odbrana and used that organization to infiltrate
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