The assassination of Archduke Franz Ferdinand (1863-1914) in the Balkans in the summer of 1914 set off a chain of events that led to the First World War (1914-18). For over a decade before, imperialistic governments, a fierce arms race, rising nationalism, and the obligations of a complex web of international alliances created an atmosphere that war was very much in the air. When Franz Ferdinand, heir to the Habsburg throne that ruled Austria-Hungary, was shot in Sarajevo on 28 June 1914 by a Serbian nationalist, individual ambition and the obligations of the pre-WWI alliance system resulted in all the major European powers declaring war on each other by the following August.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/2814/assassination-of-archduke-franz-ferdinand/.