Archduke of Austria and heir presumptive to Emperor Francis Joseph. He aimed to transform Austria-Hungary into a triple monarchy to include a Slavic kingdom. He was opposed by the Hungarians, who refused to make concessions to Slavs, and by extreme Slav nationalists (including Serbs), who saw no future for the emergent nations within the empire. On 28 June 1914, while on an inspection tour at Sarajevo, he and his wife were assassinated by Gavrilo Princip, a Serbian nationalist. The subsequent ultimatum by Austria to Serbia led directly to the outbreak of World War I.