Editing Western Front (World War I) (section)

=== First Battle of the Marne ===

{{Main|First Battle of the Marne}}

The German Army came within {{convert|70|km|mi|abbr=on}} of Paris but at the [[First Battle of the Marne]] (6–12 September), French and British troops were able to force a German retreat by exploiting a gap which appeared between the 1st and 2nd Armies, ending the German advance into France.{{sfn|Strachan|2001|pp=242–262}} The German Army retreated north of the [[Aisne (river)|Aisne]] and dug in there, establishing the beginnings of a static western front that was to last for the next three years. Following this German retirement, the opposing forces made reciprocal outflanking manoeuvres, known as the [[Race to the Sea]] and quickly extended their trench systems from the [[Switzerland|Swiss frontier]] to the [[North Sea]].{{sfn|Griffiths|1986|pp=31–37}} The territory occupied by Germany held 64 percent of French [[Pig iron|pig-iron production]], 24 percent of its [[Steelmaking|steel manufacturing]] and 40 percent of the [[Coal mining|coal industry]] – dealing a serious blow to French industry.{{sfn|Kennedy|1989|pp=265–266}}

On the [[Allies of World War I|entente side]] (those countries opposing the German alliance), the final lines were occupied with the armies of each nation defending a part of the front. From the coast in the north, the primary forces were from Belgium, the British Empire and then France. Following the [[Battle of the Yser]] in October, the Belgian army controlled a {{convert|35|km|mi|abbr=on}} length of [[West Flanders]] along the coast, known as the [[Yser Front]], along the [[Yser]] and the [[Ieperlee]] from [[Nieuwpoort, Belgium|Nieuwpoort]] to [[Boezinge]].{{sfn|Barton|Doyle|Vandewalle|2005|p=17}} Meanwhile, the British Expeditionary Force (BEF) occupied a position on the flank, having occupied a more central position.{{sfn|Baldwin|1962|p=27}}