The assassination of Archduke Franz Ferdinand of Austria in June 1914 is often regarded as the catalyst for the start of World War I. The murder by Gavrilo Princip, a Bosnian Serb nationalist, triggered a series of diplomatic crises and retaliatory actions that quickly escalated into a global conflict. Austria-Hungary's declaration of war against Serbia set off a chain reaction due to existing alliances, drawing in major powers across Europe. This event exemplified the volatile political climate of the time, revealing the fragility of peace and the impact of militarism, nationalism, and alliance systems that characterized the early 20th century.