What was known as The Great War started with war between Austria-Hungary and Serbia on 28 July 1914.
Soon it deteriorated into a global struggle involving 32 nations. The two factions were the Allies (28 nations including Great Britain, France, Russia, Italy, and the United States) and the coalition known as the Central Powers (Germany, Austria-Hungary, Turkey, and Bulgaria). An estimated ten million lives were lost and twice that number were wounded. It was fought on the Eastern and Western fronts, in the Middle East, in Africa, and at sea.
The fundamental causes of the conflict were rooted in the European history of the previous century, particularly in the political and economic policies that prevailed on the Continent after 1871, the year that marked the development of Germany as a great world power.