The historical event sparked by the assassination of Archduke Franz Ferdinand was World War I. On June 28, 1914, the archduke and his wife were killed in Sarajevo by Gavrilo Princip, a member of a nationalist group. This assassination set off a chain reaction of alliances and hostilities among the European powers. Austria-Hungary declared war on Serbia, which triggered mobilizations and declarations of war throughout Europe, ultimately leading to a full-scale global conflict involving several nations. The war lasted until 1918 and fundamentally altered the political landscape, leading to significant social, economic, and cultural changes worldwide.