Next in Timeline: Treaty of Copenhagen The First World War was a conflict that lasted six years and involved many of the major world powers fought over four continents. This was the first war ever to be truly global in scale, thus its name as a "world war". This war involved the Entente of France, Italy and Russia against the Central Powers of Germany, Austria-Hungary, and the Ottoman Empire. The only major world powers that managed to stay apart form the war were Great Britain and the United States, as they kept a policy that supported none. The losses were massive, as the fighting often occurred in disease-ridden trenches with tens of thousands of soldiers dying in a single charge. The war saw the proliferation of many new war weapons, including the first versions of the tank and the cre