Black Hand (Serbia) Balkan Wars. By this point, disagreeing with the Black Hand was dangerous, as political murder was one of their tools. It was also in 1914 that Apis allegedly decided that Archduke Franz Ferdinand, the heir-apparent of Austria, should be assassinated, as he was trying to pacify the Serbians, and if this happened then a revolution would never occur. Towards that end it is claimed that three young Bosnian Serbs were recruited to kill the Archduke. They were definitely trained in bomb throwing and marksmanship by current and former members of the Serbian military. Gavrilo Princip, Nedeljko Čabrinović and Trifko Grabež
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