Final answer:
Archduke Franz Ferdinand of Austria and his wife were assassinated in Sarajevo by Gavrilo Princip, a member of the Black Hand, on June 28, 1914, sparking the beginning of World War I.
Step-by-step explanation:
The city where Archduke Franz Ferdinand of Austria and his wife were assassinated by Gavrilo Princip is Sarajevo. This event occurred on June 28, 1914, and was the culmination of efforts by the Black Hand, a secret Serbian nationalist group.
The goal of the assassination was to break off Bosnia-Herzegovina from Austro-Hungarian rule and annex it into Serbia to form a larger Serbian state. Following the assassination, a complex web of alliances pulled various countries into conflict, marking the beginning of World War I.
Archduke Franz Ferdinand was slated to inherit the Austro-Hungarian throne and had been known to favor peaceful diplomacy, making his assassination by a young nationalist a tragic irony that catalyzed a war he might have sought to prevent.