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 of killing Franz Ferdinand came from a newspaper clipping he received in the mail at the end of March announcing Franz Ferdinand's planned visit to Sarajevo. He then showed the newspaper clipping to Princip and the next day they agreed they would kill Franz Ferdinand. Princip explained to the court he had already read about Franz Ferdinand's upcoming visit in German papers. Princip went on to testify that, at about the time of Easter (19 April), he wrote an allegorical letter to Ilić informing him of the plan to kill Franz Ferdinand. Grabež testified that he and Princip, also at