I believe it was someone by the name of Gavrilo Princip, shortly after he was arrested for this crime. Then Austria-Hungary blammed Serbia for their deaths, and Austria-Hungary sent an ultimatum to Serbia. They only agreed to 2/3 terms, Serbia goes to find help, Russia helps hen Triple Entente helps serbia. Then Triple Entente and Triple Alliance were at each other, and this is how WW1 started.
Because in 1914 the Archduke of Austria-Hungary, Franz Ferdinand, was assassinated by a Serbian Nationalist.
Neither, Franz Ferdinand of Austria-Hungary was assassinated by a Serbian nationalist from the Black Hand. Austria-Hungary declared war on Serbia, then alliances went from there.
Gavrilo Princip
Gavrilo Princip
Austria-Hungary, by a Yugoslav nationalist
The Archduke Franz Firdinand of Austria-Hungary was assassinated because Serbian's wanted to be their own nation and not part of Austria-Hungary's.
Gavrilo Princip
Arch-Duke Ferdinand of Austria-Hungary and his wife were assassinated in Sarajevo by Serbian nationalist. Within a month this resulted in the beginning of World War I.
A Serbian nationalist assassinated the Archduke Franz Ferdinand of Austria-Hungary in the Bosnia capital of Sarajevo. He murder both Franz and his wife Sofia. This event caused Austria-Hungary to declare war on Serbia.
Because a Serbian terrorist assassinated Archduke Franz Ferdinand of Austria-Hungary.
Because the the Archduke Franze Ferdinand was the heir to the Austria-Hungary throne when him and his wife when assassinated by a Serbian Nationalist in Sarejevo. Austria Hungry Gave Serbia a ultimatum and when Serbia did not follow the ultimatum Austria-Hungry declared war with Serbia
after they failed to agree to a list of demands from austria after a serbian nationalist assassinated Franz Ferdinand.