World War I

World War I, also called the Great War, was a global conflict that lasted from 1914 to 1918. It drew in the major powers of Europe, divided into two opposing alliances, along with their colonies and allies around the world. The immediate trigger was the assassination of the heir to the Austro-Hungarian throne in 1914, but the war grew out of deeper tensions including rival alliances, military build-ups and competition between the great powers. Within weeks much of Europe was at war.

On the Western Front, running through Belgium and France, the fighting settled into a long stalemate of trench warfare. Soldiers on both sides dug networks of trenches facing each other across a devastated no man's land, and repeated offensives gained little ground at enormous human cost. Battles such as those around Verdun and in the region of Flanders became symbols of the war's scale and futility. The conflict introduced or expanded fearsome weapons, including the machine gun, heavy artillery, the airplane and the Zeppelin airship, and the use of poison gas as a chemical weapon.

The war spread far beyond the Western Front, with major fighting in Eastern Europe, the Middle East and at sea. After four years of attrition the alliance opposing Germany and its partners prevailed, and an armistice ended the fighting on 11 November 1918. The cost was staggering, with millions killed and wounded. The war reshaped the map of Europe, brought down several empires, and its unsettled aftermath contributed to the tensions that led to a second world war two decades later.

Frequently asked questions

When did World War I take place?

From 1914 to 1918. The fighting ended with an armistice on 11 November 1918.

What was trench warfare?

A form of fighting in which opposing armies dug long lines of trenches facing each other. It dominated the Western Front and produced a costly stalemate with little movement.

Why is it called the Great War?

It was given that name because of its unprecedented scale and destruction. The term “World War I” came into wider use after a second world war followed.