Russia and Germany clash in the Battle of Tannenberg in August 1914; France defeats the German army in the Battle of the Marne; colonial troops join the global conflict.

The war was to be short and glorious. But fear spreads. While the generals refuse to change their tactics, men are being killed on an unprecedented scale. An entire generation could be lost and yet the war goes on.

Russia 1917: Tsar Nicholas II of Russia is the first Emperor to fall as a result of the war. Will the Russian revolution mean an end to their involvement? A new German offensive could pull the United States into the conflict and fuel the flames of war. Mutinies break out on both sides.