On June 28, 1914, Archduke Franz Ferdinand of Austria, the heir to the throne of Austria-Hungary, and his wife, Sophie, Duchess of Hohenberg, were assassinated in Sarajevo, the provincial capital of Bosnia-Herzegovina (formally annexed by Austria-Hungary in 1908).
The assassin was Gavrilo Princip, a Bosnian Serb and Yugoslav nationalist who was a member of the Black Hand, a secret society dedicated to the unification of all South Slavic peoples into a single state.
The assassination triggered a chain of events that led to the outbreak of World War I.