Which historic figure's assassination is often cited as a catalyst for the outbreak of World War I?

The assassination of Archduke Franz Ferdinand is often cited as the catalyst for the outbreak of World War I due to its direct impact on the political landscape of Europe at the time. Ferdinand, the heir to the Austro-Hungarian throne, was assassinated on June 28, 1914, in Sarajevo by Gavrilo Princip, a member of the nationalist group known as the Black Hand.

This act set off a chain reaction of events that escalated tensions between major European powers. Austria-Hungary perceived the assassination as a threat and issued an ultimatum to Serbia, which was viewed as an ally of the assassin through nationalist ties. The rigid alliances formed between countries, such as Germany supporting Austria-Hungary and Russia supporting Serbia, quickly drew multiple nations into the conflict. This domino effect of alliances and military mobilizations ultimately led to the declaration of war.

While figures like Tsar Nicholas II played significant roles during the war, and leaders such as Winston Churchill and Woodrow Wilson were pivotal during and after the conflict, it was Ferdinand's assassination that ignited the immediate hostilities, making it a critical event in the history of World War I.