Allan Kent PowellUtah History Encyclopedia, 1994 Known as “The Great War” until the outbreak of World War II, World War I began on 1 August 1914 and ended with armistice on 11 November 1918. The two warring sides were the Allies—comprised of Russia, France, Great Britain, Italy, United States, Japan, Romania, Belgium, Serbia, Greece, Portugal, and Montenegro; and the Central …