Archduke Franz Ferdinand was the heir to the throne of Austria-Hungary. Hoping to ease tensions with the Balkan nations, he arranged to tour Bosnia-Herzegovina with his wife, Sophie. On June 28, 1914, an assassin killed Franz Ferdinand and Sophie in Sarajevo. The murderer, a young Bosnian Serb named Gavrilo Princip, had links to a Serbian terrorist group called the Black Hand.
The assassination of Franz Ferdinand gave Austria-Hungary a reason to attack Serbia, its long-time enemy in the Balkans. Backed by Germany’s promise of support, Austria-Hungary sent a list of demands to Serbia. Serbia accepted most of the demands and offered to settle the rest through an international conference. Austria-Hungary rejected the offer and declared war on Serbia on July 28.
Te assassination resulted into the declaration of war.