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
World War I 1918 influenza pandemic, which caused between 50 and 100 million deaths worldwide. Military losses were exacerbated by new technological and industrial developments and the tactical stalemate caused by gruelling trench warfare. It was one of the deadliest conflicts in history and precipitated major political changes, including the Revolutions of 1917–1923, in many of the nations involved. Unresolved rivalries at the end of the conflict contributed to the start of World War II about twenty years later. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July