WORLD WAR I

World War I is known as the First World War, the Great War, or the War to End All Wars,was a war of the universe originating in Europe and lasted from 28 July 1914 to 11 November 1918. Over than 70 million military personnel, including 60 million Europeans, were assembled in one of the largest wars in history.more than nine millioncombatants and seven million civilians died as a result of the war , morality rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. It among one of the deadliest conflicts in history, and paved the way for Paramount political changes, including revolutions in many of the nations involved. Unresolved rivalries still extant at the end of the conflict contributed to the start of the Second World War only twenty-one years later.

The war drew in all the world's economic great powers assembled in two opposing alliances: the Allies versus the Central Powers of Germany and Austria-Hungary.

Even though Italy was a member of the Triple Alliance along with Germany and Austria-Hungary, it did not join the Central Powers, as Austria-Hungary had taken the offensive against the terms of the alliance.These union was 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.

The activation for the war was caused by the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalistGavrilo Princip in Sarajevo on 28 June 1914. This set off a diplomatic crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia, and entangled international alliances formed over the previous decades were invoked. Within weeks, the major powers were at war and the conflict soon spread around the world.

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. After the German march on Paris was halted in the Battle of the Marne, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917. On the Eastern Front, the Russian army led a triumphant campaign against the Austro-Hungarians, but the Germans stopped itsinvasion of East Prussia in the battles of Tannenberg and the Masurian Lakes. In November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus,Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Powers;Romania joined the Allies in 1916, as did the United States in 1917.

By the end of the war or soon after, the German Empire, Russian Empire, Austro-Hungarian Empireand the Ottoman Empire ceased to exist. National borders were redrawn, with several independent nations restored or created, and Germany's colonies were parceled out among the victors. During the Paris Peace Conference of 1919, the Big Four imposed their terms in a series of treaties. TheLeague of Nations was formed with the aim of preventing any repetition of such a conflict. This effort failed, and economic depression, renewed nationalism, weakened successor states, and feelings of humiliation eventually contributed to the start of World War II