World War I’s Eastern Front was one of the largest military campaigns by area ever fought on Earth.  Stretching from the Baltic to the Black Seas, Russia faced Germany, Austria-Hungary, Bulgaria, and the Ottomans in three unrelenting years of total war that claimed sixteen million casualties.  In the end, the Russian Empire collapsed and Vladimir Lenin built the Soviet Union out of the ashes of revolution.  And so ended Russia’s involvement in The War.