World War I

World War I or the First World War, often abbreviated as WWI or WW1, known contemporaneously as the Great War, was a major global conflict lasting from 1914 to 1918. It was fought between two coalitions, the Allies and the Central Powers. Fighting took place throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. The first decade of the 20th century saw increasing diplomatic tension between the European great powers. This reached a breaking point on 28 June 1914, when a Bosnian Serb named Gavrilo Princip assassinated Archduke Franz Ferdinand, heir to the Austro-Hungarian throne. Austria-Hungary held Serbia responsible, and declared war on 28 July. Russia came to Serbia's defence, and by 4 August, Germany, France and Britain were drawn into the war, with the Ottoman Empire joining in November the same year. German strategy in 1914 was to first defeat France by moving and attacking through Belgium before turning to face Russia. However, this failed, and by the end of 1914, the Western Front consisted of a continuous line of trenches stretching from the English Channel to Switzerland. The Eastern Front was more fluid, but neither side could gain a decisive advantage, despite a series of costly offensives. As the war expanded onto more fronts, Bulgaria, Romania, Greece, Italy and others also joined in between 1915 and 1917. In early 1917, the United States entered the war on the side of the Allies, while in late 1917, the Bolsheviks seized power in the Russian October Revolution, making peace with the Central Powers in early 1918. Germany then launched an offensive in the west on March 1918, but despite initial success, it left the German army exhausted and demoralised, and a successful Allied counter-offensive later the same year caused a collapse of the German frontline. By the end of 1918, Bulgaria, the Ottoman Empire and Austria-Hungary agreed to armistices with the Allies, leaving Germany isolated. Facing revolution at home and with his army on the verge of mutiny, Kaiser Wilhelm II abdicated on 9 November.