Gavrilo Princip (25 July 1894(1894-07-25) - 28 April 1918) was a Bosnian Serb who was a Yugoslav nationalist associated with the movement Mlada Bosna (Young Bosnia). Princip assassinated Archduke Franz Ferdinand of Austria and his wife, Sophie, Duchess of Hohenberg, in Sarajevo on 28 June 1914. Princip and his accomplices were arrested and implicated a number of members of the Serbian military, leading Austria-Hungary to issue a demarche to Serbia known as the July Ultimatum. This set off a chain of events that led to World War I.