On June 28, 1914, Archduke Franz Ferdinand of Austria, heir to the Austro-Hungarian throne, was assassinated in Sarajevo, the capital of Bosnia-Herzegovina (which had been annexed by Austria-Hungary in 1908). The assassin was Gavrilo Princip, a Bosnian Serb nationalist who was a member of the Black Hand, a secret society dedicated to the unification of all South Slavic peoples into a single state.
The assassination of Archduke Franz Ferdinand was the spark that ignited World War I. Here are some of the key factors that led to the outbreak of war:
* Austria-Hungary's ultimatum to Serbia: In the aftermath of the assassination, Austria-Hungary issued an ultimatum to Serbia that was designed to be unacceptable. The ultimatum included demands that Serbia publicly condemn the assassination, punish those responsible, and allow Austrian officials to participate in the investigation. Serbia accepted most of the demands but rejected the one that would have allowed Austrian officials to participate in the investigation, arguing that this would violate its sovereignty.
* Germany's "blank check" to Austria-Hungary: Before issuing its ultimatum to Serbia, Austria-Hungary obtained a promise of support from Germany. This promise, known as the "blank check," assured Austria-Hungary that Germany would support it in the event of war with Russia, which was Serbia's ally.
* Russia's mobilization: When Austria-Hungary declared war on Serbia on July 28, 1914, Russia responded by mobilizing its army. This prompted Germany to declare war on Russia on August 1 and on France, Russia's ally, on August 3. Britain declared war on Germany on August 4, after Germany violated Belgian neutrality by invading Belgium.
The assassination of Archduke Franz Ferdinand was the catalyst that set off a chain of events that led to the outbreak of World War I. The war would last for four years and result in the deaths of millions of people.