Archduke Franz Ferdinand of Austria was assassinated by Gavrilo Princip on June 28, 1914. This event took place in Sarajevo, Bosnia, and it was a pivotal moment that set off a chain reaction leading to the outbreak of World War I. Princip was a member of the nationalist group called the Black Hand, which sought to promote the interests of South Slavic peoples and was opposed to Austro-Hungarian rule. The assassination heightened existing tensions between nations, particularly Austria-Hungary and Serbia, ultimately resulting in declarations of war and the escalation of a local conflict into a global war.