World War 1

World War 1 (1914–18) International conflict, also known as the Great War, precipitated by the assassination of the Austrian Archduke Franz Ferdinand by Serbs in Sarajevo (June 28, 1914). Austria declared war on Serbia (July 28), Russia mobilized in support of Serbia (from July 29), Germany declared war on Russia (August 1) and France (August 3), and Britain declared war on Germany (August 4). World War 1 resulted from growing tensions in Europe, exacerbated by the rise of the German Empire since 1871 and the decline of Ottoman power in the Balkans. The chief contestants were the Central Powers (Germany and Austria) and the Triple Entente (Britain, France, and Russia). Many other countries were drawn in: Ottoman Turkey joined the Central Powers in 1914, Bulgaria in 1915. Italy joined the Western Allies in 1915, Romania in 1916 and, decisively, the USA in 1917. Russia withdrew following the Russian Revolution (1917). In Europe fighting was largely static. The Allies checked the initial German advance through Belgium at the Marne, and the Western Front settled into a war of attrition, with huge casualties but little progress. On the Eastern Front, the Germans checked the initial Russian advance, and overran Poland before stagnation set in. An Anglo-French effort to relieve the Russians by attacking Gallipoli (1916) failed. Italy and Austria became bogged down on the Isonzo Front. Campaigns were also fought outside Europe – against the Turks in the Middle East, and the German colonies in Africa and the Pacific. Only one major naval battle was fought, at Jutland (1916). The naval blockade of Germany caused severe food shortages and helped to end the war. An armistice was agreed in November 1918 and peace treaties were signed at Versailles (1919). An estimated 10 million people died in the war.