Deadliest single days of World War I

While it is most famous for the trench warfare stalemate that existed on Europe's Western Front, in other theatres of combat the fighting was mobile and often involved set-piece battles and cavalry charges.

The Eastern Front often took thousands of casualties a day during the major offensive pushes, but it was the west that saw the most concentrated slaughter.

It was in the west that the newly industrialized world powers could focus their end products of the military–industrial complex.

The Imperial German war council had initiated the Schlieffen Plan which involved multiple armies flooding through the borders of Belgium and France.

On August 22, 1914, during the Battle of the Frontiers, five separate French armies engaged the German invaders independently of each other.