World War I
World War I (1914-1918) was a global conflict centered in Europe that resulted in the deaths of an estimated 20 million people and reshaped the political map of the continent.
A single assassination in the Balkans set off a chain of alliance obligations so rigid that most of Europe was at war within weeks, with almost no one having wanted it to escalate that far.
A Single Assassination Sparks a World War
The war began following the assassination of Archduke Franz Ferdinand of Austria-Hungary in Sarajevo in June 1914, an event that triggered a rapid chain reaction of alliance obligations, drawing major European powers into conflict within just weeks.
A Web of Alliances
Europe's complex system of pre-war alliances meant that a regional dispute in the Balkans quickly escalated into a continental war, pitting the Allied Powers (including Britain, France, and Russia) against the Central Powers (led by Germany and Austria-Hungary).
The Horror of Trench Warfare
The war became infamous for grueling, static trench warfare along the Western Front, where new technologies including machine guns, poison gas, and tanks produced enormous casualties for often minimal territorial gains.
America Enters the War
The United States entered the war in 1917, providing crucial fresh troops and resources that helped tip the balance decisively in favor of the Allied Powers after years of costly stalemate.
A Peace That Sowed Future Conflict
The war ended in November 1918 with the defeat of the Central Powers, and the subsequent Treaty of Versailles imposed harsh economic and territorial terms on Germany that historians widely view as having contributed significantly to the conditions that gave rise to Nazism and World War II two decades later.
