Veljko Čubrilović Veljko Čubrilović Veljko Čubrilović (Serbian Cyrillic: Вељко Чубриловић; 6 June 1886 – 3 February 1915) was a Bosnian Serb who was involved in the assassination of Archduke Franz Ferdinand of Austria. He was born in Gradiška, Bosnia and Herzegovina and became a schoolteacher in Priboj Majevički. In 1914, as a member of the Black Hand secret society, he agreed to help Gavrilo Princip, Nedeljko Čabrinović, and Trifko Grabež assassinate Archduke Franz Ferdinand. His brother, Vaso Čubrilović, was also involved in the plot. On Sunday, 28 June 1914, Franz Ferdinand and Sophie von Chotkova were assassinated by Gavrilo Princip. Princip and
Assassination of Archduke Franz Ferdinand advocate of increased federalism and widely believed to favor trialism, under which Austria-Hungary would be reorganized by combining the Slavic lands within the Austro-Hungarian empire into a third crown. A Slavic kingdom could have been a bulwark against Serb irredentism, and Franz Ferdinand was therefore perceived as a threat by those same irredentists. Princip later stated to the court that preventing Franz Ferdinand's planned reforms was one of his motivations. The day of the assassination, June 28 (June 15 in the Julian calendar), is the feast of St. Vitus. In Serbia, it is called Vidovdan and commemorates the 1389 Battle