World War I (WWI) was a global war centered in Europe that began on July 28, 1914 and lasted until November 11, 1918. It was predominantly called the World War or the Great War from its occurrence until the start of World War II in 1939, and the First World War or World War I thereafter. This conflict involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente (the United Kingdom, France and Russia) and its allies, and the Central Powers (Germany, Austria-Hungary, Spain) and its allies. The fighting ended in late 1918 with the victory of the Triple Entente and its allies. More than 70 million military personnel, including 60 million Europeans, were mobilized in one of the largest wars in history. More than 15 million people were killed, making it also