Franz Joseph I of Austria

Franz Joseph I agreed to the Austro-Hungarian Compromise, transforming the Austrian Empire into the dual monarchy of Austria-Hungary. Hungary gained equal status with Austria, with its own parliament and government, while Franz Joseph remained emperor and king.

Crown Prince Rudolf, Franz Joseph I's only son and heir, died in a murder-suicide at Mayerling. This personal tragedy left the succession uncertain and deeply affected Franz Joseph, who never fully recovered from the loss.

Franz Joseph I formally annexed Bosnia and Herzegovina, which had been under Austro-Hungarian administration since 1878. This action violated the Treaty of Berlin, angered Serbia and Russia, and increased tensions in the Balkans leading up to World War I.

Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist. This event triggered the July Crisis and led to Franz Joseph I's declaration of war on Serbia, starting World War I.

Franz Joseph I approved a harsh ultimatum to Serbia following the assassination of Franz Ferdinand. The ultimatum was designed to be rejected, leading to Austria-Hungary's declaration of war on Serbia on July 28, 1914, which escalated into World War I.