The Germany battle plan for World War I, the Schlieffen Plan anticipated a rapid victory in the West and then a turn Eastward. While the initial battles of the war collectively known as the Frontier Battles has been harder than the Germans had anticipated the outcome had been favorable for the Germans. They had forced back the French and British troops all the way across Northern France to the outskirts of Paris. It looked like the Germans might achieve their goal capture Paris and end the war in the West.
The French and the British were not willing to give up and the French counterattacked on September 4th. The French Sixth Army and the BEF launched their counterattack on the flanks of the German lines. The Germans reacted by pulling their 1st army troops back to the Northern banks of the Marne River. By doing so this created a 30 mile gap between the German First and Second Army. The British Expeditionary Forces and the French Fifth Army promptly moved through the gap and attacked the German flanks. The BEF captured bridges across the Marne and establish a bridgehead there. The German 1st Army was still hoping to defeat and outnumber French 6th army but the French army sent 6,000 reinforcements by taxi from Paris and they succeeded in stabilizing the French lines. With British and French troops streaming through the gap, the Germans realized that their forces were in danger of being enveloped. The Germans began a general withdrawal. The German forces withdrew 40 miles back to the Ainse River.
Two million men participated in the First Battle of the Marne. While the exact number of casualties has never been accurately determined, over 500,000 soldiers were killed or wounded in the battle with both sides losing an equal number of troops. It was the bloodiest battle on the Western Front. However the French and British victory ended the hopes of the Germans for a quick victory on the Western Front. The Schiefflen Plan had failed and General Motke the German Chief of Staff is said to told the Kaiser “the war is lost”. What would follow would be years of trench warfare that would kill or wound a generation of youth.