"This was to become the Battle of the Somme (French: Bataille de la Somme), also known as the Somme Offensive. It became one of the largest battles of the First World War and continued from 1 July to 18 November 1916. By the time the winter set in and fighting had receded, more than 1.5 million casualties had been suffered by the forces involved. It is now understood to have been one of the bloodiest military operations ever recorded."
'The German Empire, being the defenders and fighting from extremely well prepared defensive systems suffered too, a German record describing the battle as "..the muddy grave of the German Army."'
http://en.wikipedia.org/wiki/Battle_of_the_Somme
It's not mentioned in that Wikipedia entry (that I could find anyway) but I remember from history class that come consider the Battle of the Somme to be a turning point in WWI.
"having the french on your side is like having the weakest kid defending"
- None of the weakest kids in any school I've ever attended had nuclear submarines.
"In a world of global deceit, telling the truth is a revolutionary act." George Orwell