Trifko Grabež society. For the next two years he spent most of his spare time with other nationalists who favoured a union between Bosnia and Herzegovina and Serbia. When it was announced that Archduke Franz Ferdinand, the heir to the throne of Austro-Hungarian Empire, was going to visit Bosnia and Herzegovina in June 1914, Colonel Dragutin Dimitrijević, the chief of the Intelligence Department in the Serbian Army and head of the Black Hand, sent seven men, Grabež, Nedeljko Čabrinović, Vaso Čubrilović, Cvjetko Popović, Danilo Ilić, Muhamed Mehmedbašić and Gavrilo Princip to Sarajevo to assassinate him. Each man was given either a revolver
Assassination of Archduke Franz Ferdinand Popović shortly after Easter (Orthodox Easter as given by Dedijer: 19 April 1914), for the assassination, as evidenced by the testimony of Ilić, Čubrilović, and Popović at the Sarajevo trial. Three youths – Gavrilo Princip, Trifko Grabež, and Nedeljko Čabrinović – Bosnian Serb subjects of Austria-Hungary, living in Belgrade, testified at the Sarajevo trial that at about the same time (a little after Easter), they were eager to carry out an assassination and approached a fellow Bosnian Serb and former guerrilla fighter known to be well connected and with access to arms, Milan Ciganović, and through him Major Tankosić and