Instability in Europe is fueled by Germany's growing militarism, Kaiser Wilhelm II's obsession to match the British Royal Navy, and French and German war plans before the assassination of Archduke Franz Ferdinand of Austria triggers combat.

In 1915, combat takes on new dimensions with German zeppelins bombing British cities, German U-boats attacking neutral shipping and the unleashing of chemical warfare.

In 1916, the Germans begin a battle of attrition at Verdun and the Russians launch an offensive to try to relieve pressure on their French ally.

In 1917, hundreds of thousands of soldiers desert the Russian army, Germany shifts forces to the Western Front and the United States enters the war.

In 1918, German storm troopers achieve devastating results as the Allies lose 400,000 men in just three weeks.