Respuesta :
Gavrilo Princip, a member of the black hand society, assassinated Archduke Franz Ferdinand and his wife, triggering the military alliances that declared on each other consecutively.
hope this helps
Answer:
Serbian nationalist Gavrilo Princip
Explanation:
Because he killed Archduke Franz Ferdinand heir to the Austro-Hungarian Empire. Because of this, Austria-Hungary declares war on Serbia, effectively beginning the First World War.