Unlike the stalemate of the trenches in Flanders, the little-known eastern front of the First World War was a war of movement that cost 12 million casualties, including female combatants. It spanned thousands of miles from the Baltic to the Black and Caspian seas, before spreading north to the Arctic and east to the Pacific, embroiling several thousand British Empire and US soldiers in secret operations in the far North, Siberia and Ukraine. After the war, Britain and France rebuilt themselves and the US was unaffected. In the east, this savage conflict of atrocities destroyed all the belligerents: the German, Austro-Hungarian, Ottoman and Russian empires. Berlin ended the eastern front hostilities prematurely at Brest-Litovsk, having covertly financed and promoted the Bolshevik Revolution. This unleashed a 'rainbow of death' with the Red Army using famine, poison gas and concentration camps against the Green, Blue and Black armies. This remarkable story of war and attrition is brought to life by personal accounts from all sides.