The war pitted the Central Powers—mainly Germany, Austria-Hungary, and Turkey—against the Allies—mainly France, Great Britain, Russia, Italy, Japan, and, from 1917, the United States. It ended with the defeat of the Central Powers. The war was virtually unprecedented in the slaughter, carnage, and destruction it caused. World War IEncyclopædia Britannica, Inc.World War I was one of the great watersheds of 20th-century geopolitical history.
https://www.britannica.com/event/World-War-I
Loss of the Formidable. In 1914 the Germans had already been employing U-boats to devastating effect against British warships, and the New Year brought yet another submarine triumph with the sinking of HMS Formidable by U-24 in the English Channel in the early morning of January 1, 1915.
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On July 28, Austria-Hungary declared war on Serbia, and the tenuous peace between Europe’s great powers collapsed. Within a week, Russia, Belgium, France, Great Britain and Serbia had lined up against Austria-Hungary and Germany, and World War I had begun.
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Gallipoli Campaign (1915-16) and Battles of the Isonzo (1915-17) With World War I having effectively settled into a stalemate in Europe, the Allies attempted to score a victory against the Ottoman Empire, which had entered the conflict on the side of the Central Powers in late 1914.
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World War I’s Eastern Front and Revolution in Russia (1914-17) On the Eastern Front of World War I, Russian forces invaded East Prussia and German Poland, but were stopped short by German and Austrian forces at the Battle of Tannenberg in late August 1914.
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It led to the fall of four great imperial dynasties (in Germany, Russia, Austria-Hungary, and Turkey), resulted in the Bolshevik Revolution in Russia, and, in its destabilization of European society, laid the groundwork for World War II.
https://www.britannica.com/event/World-War-I
WWI Centennial: New Year in a World at War. The First World War was an unprecedented catastrophe that shaped our modern world. Erik Sass is covering the events of the war exactly 100 years after they happened. This is the 161st installment in the series.
http://mentalfloss.com/article/60893/wwi-centennial-new-year-world-war
An escalation of threats and mobilization orders followed the incident, leading by mid-August to the outbreak of World War I, which pitted Germany, Austria-Hungary and the Ottoman Empire (the so-called Central Powers) against Great Britain, France, Russia, Italy and Japan (the Allied Powers).
http://www.history.com/topics/world-war-i/world-war-i-history
World War I. World War I, also called First World War or Great War, trench warfare: British soldier in a trench on the Western Front, World War IHulton Archive/Getty Imagesan international conflict that in 1914–18 embroiled most of the nations of Europe along with Russia, the United States, the Middle East, and other regions.
https://www.britannica.com/event/World-War-I
World War I at Sea (1914-17) After the Battle of Dogger Bank in January 1915, the German navy chose not to confront Britain’s mighty Royal Navy in a major battle for more than a year, preferring to rest the bulk of its strategy at sea on its lethal U-boat submarines.
http://www.history.com/topics/world-war-i/world-war-i-history
what year was wwi
World War I lasted from 1914 to 1917 World War I year is between 1914 and 917.