The notable worldwide event that began in 1914 and involved most of the world's powers was World War I. Triggered by the assassination of Archduke Franz Ferdinand of Austria, this conflict saw major alliances, including the Allies and Central Powers, engaging in prolonged warfare. The war introduced new military technologies and tactics, leading to unprecedented casualties and destruction. Its aftermath reshaped geopolitical boundaries and resulted in important treaties, like the Treaty of Versailles, dramatically influencing future conflicts, including World War II and the course of 20th-century history.