Archduke Franz Ferdinand of Austria was assassinated in Sarajevo on June 28, 1914, an event that famously triggered World War I. His assassination by Gavrilo Princip, a member of the nationalist group known as the Black Hand, set off a chain reaction of alliances and mobilizations among European powers. This act of violence escalated existing tensions between Austria-Hungary and Serbia, bringing in other nations due to alliances and leading to a global conflict that reshaped political borders, economies, and societies in the ensuing years.