World War I, also known as the Great War, was a global conflict that lasted from July 28, 1914, to November 11, 1918. It involved the majority of the world's great powers and spanned four continents. The war was characterized by trench warfare, technological innovation, and the unprecedented scale of destruction.


The main causes of World War I included militarism, alliances, imperialism, and the assassination of Archduke Franz Ferdinand of Austria-Hungary in Sarajevo in 1914. The war initially involved the Allied Powers, including France, Russia, and the United Kingdom, against the Central Powers, primarily Germany, Austria-Hungary, and the Ottoman Empire.


The conflict saw the widespread use of new military technologies such as machine guns, tanks, and chemical weapons, contributing to the high casualty rates. The Western Front, characterized by extensive trench systems, became a symbol of the war's stagnant and brutal nature.


As the war progressed, more nations joined the conflict, including the United States in 1917. The Russian Revolution in 1917 led to Russia's withdrawal from the war. The entry of fresh American troops and the declining morale of the Central Powers contributed to the Allies gaining the upper hand.


The war concluded with the signing of the Armistice on November 11, 1918, effectively ending the fighting on the Western Front. The Treaty of Versailles, signed in 1919, formally ended the state of war between Germany and the Allied Powers, imposing harsh conditions on Germany and setting the stage for future geopolitical tensions.


World War I had profound and far-reaching consequences, including the redrawing of national borders, the collapse of empires, and the League of Nations' establishment, an early attempt at international cooperation. The war also laid the groundwork for World War II, shaping the course of the 20th century.