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
.380 ACP 42; all three being designed to be lighter than blowback operated .380 ACP weapons. There have also been some relatively diminutive (blowback-operated) submachine guns, such as the Ingram MAC-11 and the Czech vz. 83. The .380 ACP has experienced very widespread use in the years since its introduction (1908 United States, 1912 Europe). In 1914, it was used by Gavrilo Princip to assassinate Archduke Franz Ferdinand and his wife Sophia, the event which is credited with starting World War I. It was later adopted by the armies of at least five European nations as their standard pistol cartridge before World