World War I

World War I (abbreviated as WW-I, WWI, or WW1), also known as the First World War, the Great War, the World War (prior to the outbreak of the Second World War), and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Allies of World War I centred around

the Triple Entente and the Central Powers, centred around the Triple Alliance. More than 70 million military personnel were mobilized in one of the largest wars in history. More than 15 million people were killed, making it one of the deadliest conflicts in history. During the conflict, the industrial and scientific capabilities of the main combatants were entirely devoted to the war effort. The assassination, on 28 June 1914, of Archduke Franz Ferdinand of Austria, the heir to the throne of Austria-Hungary, is seen as the immediate trigger of the war, though long-term causes, such as imperialistic foreign policy, played a major role. The archduke's assassination at the hands of Serbian nationalist Gavrilo Princip resulted in demands against the Kingdom of Serbia. Several alliances that had been formed over the past decades were invoked, so