[custom_adv] World War I , also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. [custom_adv] More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. [custom_adv] Over nine million combatants and seven million civilians died as a result of the war (including the victims of a number of genocides), a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. [custom_adv] It was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved and to the Second World War twenty-one years later. [custom_adv] The war drew in all the world's economic great powers, assembled in two opposing alliances: the Allies (based on the Triple Entente of the Russian Empire, the French Third Republic, and the United Kingdom of Great Britain and Ireland) versus the Central Powers of Germany and Austria-Hungary. [custom_adv] Although Italy was a member of the Triple Alliance alongside Germany and Austria-Hungary, it did not join the Central Powers, as Austria-Hungary had taken the offensive against the terms of the alliance. [custom_adv] These alliances were reorganised and expanded as more nations entered the war: Italy, Japan and the United States joined the Allies, while the Ottoman Empire and Bulgaria joined the Central Powers. [custom_adv] On 25 July Russia began mobilisation and on 28 July the Austro-Hungarians declared war on Serbia. Germany presented an ultimatum to Russia to demobilise, and when this was refused, declared war on Russia on 1 August. [custom_adv] Being outnumbered on the Eastern Front, Russia urged its Triple Entente ally France to open up a second front in the west. Back in 1870, the Franco-Prussian War had ended the Second French Empire and ceded the provinces of Alsace-Lorraine to a unified Germany. [custom_adv] Bitterness over that defeat and the determination to retake Alsace-Lorraine made the acceptance of Russia's plea for help an easy choice, so France began full mobilisation on 1 August and, on 3 August, Germany declared war on France. [custom_adv] The border between France and Germany was heavily fortified on both sides so according to the Schlieffen Plan, Germany then invaded neutral Belgium and Luxembourg before moving towards France from the north, leading the United Kingdom to declare war on Germany on 4 August due to their violation of Belgian neutrality. [custom_adv] The Russian government collapsed in March 1917, and a revolution in November followed by a further military defeat brought the Russians to terms with the Central Powers via the Treaty of Brest Litovsk, which granted the Germans a significant victory.