Franz Ferdinand was the heir to the Austro-Hungarian Empire, and his assassination was a direct threat to the stability of Europe. The Austro-Hungarian government was quick to blame Serbia for the assassination and used it as a pretext to declare war on Serbia. Russia, as an ally of Serbia, then declared war on Austria-Hungary. Germany, as an ally of Austria-Hungary, then declared war on Russia and France.
The assassination of Franz Ferdinand and his wife was a pivotal moment in history that led to the outbreak of one of the most destructive wars in history.