First Battle of the Marne

The First Battle of the Marne was a battle of the First World War fought from 5 to 12 September 1914. The German army invaded France with a plan for winning the war in 40 days by occupying Paris and destroying the French and British armies (Allies/Entente). The Germans had initial successes in August. They were victorious in the Battles of Mons and the Frontiers and overran a large area of northern France and Belgium. In what is called the Great Retreat the Germans pursued the retreating Franco/British forces more than southward. The French and British halted their retreat in the Marne River valley while the Germans advanced to from downtown Paris. With the battlefield reverses of August, Field Marshal John French, commander of the British Expeditionary Force (BEF), lost faith in his French allies and began to plan for a British retreat to port cities on the English Channel for an evacuation to Britain. However, the French commander Joseph Joffre maintained good order in his retreating army and was able to reinforce it by bringing in additional manpower from his eastern flank and integrating military reserve units into the regular army. By early September, the Franco/British forces outnumbered the Germans who were exhausted after a month-long campaign, had outrun their supply lines, and were suffering shortages. On 3 September the military governor of Paris, Joseph Simon Gallieni, perceived that the German right flank was vulnerable and positioned his forces to attack. On 4 September Joffre gave the order to launch a counteroffensive. The battle took place between Paris and Verdun, a west to east distance of . The point of decision and the heaviest fighting was in the western one-half of that area. By 9 September, the success of the Franco–British counteroffensive left the German 1st and 2nd Armies at risk of encirclement, and they were ordered to retreat to the Aisne River. The retreating armies were pursued by the French and British. The German armies ceased their retreat after on a line north of the Aisne River, where they dug in on the heights and fought the First Battle of the Aisne.