The early 20th century was a period of immense tension among European powers, characterized by military build-up, intense nationalism, and complex alliances. On June 28, 1914, Archduke Franz Ferdinand of Austria-Hungary was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist. This event, though seemingly isolated, triggered a chain reaction among nations bound by treaties and allegiances. Austria-Hungary, backed by Germany, saw an opportunity to address longstanding conflicts in the Balkans, while Russia aligned with Serbia. This cascade of alliances and political maneuvers led to the rapid escalation from regional tensions to global warfare.