Final answer:
The assassination of Archduke Franz Ferdinand is a singular event in Balkan history due to its direct consequence of starting World War I. Unlike other regional disturbances, it triggered the Austro-Hungarian ultimatum against Serbia and the subsequent activation of alliances, igniting a global war.
Step-by-step explanation:
The assassination of Archduke Franz Ferdinand stands out in the history of the Balkan Peninsula due to its critical role in igniting World War I. While the Balkans had been a hotspot for ethnic strife and nationalist movements, the events of June 28, 1914, directly inflamed tensions among Europe's great powers. The Black Hand, a Serbian nationalist organization, provided the assassins with the aim of detaching Bosnia-Herzegovina from Austria-Hungary to create a Greater Serbia. The assassination, carried out by Gavrilo Princip, differed from other regional incidents primarily because it led to Austria-Hungary's ultimatum against Serbia, which triggered the activation of a complex web of alliances, and initiated a series of events that escalated into a global conflict.
When considering other events in the Balkans, they largely focused on the independence and national ambitions of various ethnic groups under imperial rule. However, none had the catalytic effect on a global scale equivalent to the assassination of the heir to the Austro-Hungarian Empire. This singular event linked domestic nationalist aspirations with international diplomatic crises, ultimately setting the stage for World War I.