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
Europe War I was fought between 1914 and 1918. It started when Archduke Franz Ferdinand of Austria was assassinated by the Yugoslav nationalist Gavrilo Princip. Most European nations were drawn into the war, which was fought between the Entente Powers (France, Belgium, Serbia, Portugal, Russia, the United Kingdom, and later Italy, Greece, Romania, and the United States) and the Central Powers (Austria-Hungary, Germany, Bulgaria, and the Ottoman Empire). The war left more than 16 million civilians and military dead. Over 60 million European soldiers were mobilised from 1914 to 1918. Russia was plunged into the Russian Revolution, which threw down the