The assassination of Archduke Franz Ferdinand in 1914 was a significant trigger for World War I. The event set off a series of alliances, conflicts, and diplomatic failures that plunged many nations into war. It highlighted the existing tensions in Europe, including nationalism, militarism, and colonial competition. The archduke's murder by a Bosnian Serb nationalist led Austria-Hungary to declare war on Serbia, igniting a conflict that eventually involved many countries and reshaped the global political landscape in the 20th century.