There were over 900,000 German soldiers under the leadership of General Helmuth von Moltke. The French and British had over 1,082,000 soldiers.
After invading neutral Belgium and advancing into northeastern France by the end of August 1914, German forces were nearing Paris, spurred on by punishing victories that forced five French armies into retreat after the Battles of the Frontiers at Lorraine, Ardennes, Charleroi and Mons.
On September 4 Joseph Jacques Césaire Joffre, French general, convinced, the military governor of Paris General J.-S. Gallieni’s arguments, decisively ordered his whole left wing to turn about from their retreat and to begin a general offensive against the Germans’ exposed right flank on September 6.
On September 6, 1914, some 30 miles northeast of Paris, the French 6th Army under the command of General Michel-Joseph Manoury attacks the right flank of the German 1st Army, beginning the decisive First Battle of the Marne at the end of the first month of World War I.
A French offensive in Lorraine prompted German counter-attacks that threw the French back onto a fortified barrier. The German northern wing was weakened further by the removal of 11 divisions to fight in Belgium and East Prussia.
The counterattack of the French 5th and 6th Armies and the British Expeditionary Force developed into the First Battle of the Marne, a general counter-attack by the French Army. By 11 September the Germans were in full retreat.
After a few days of fighting, the Germans were forced to retreat. They retreated back to Aisne River in northern France. Here they built long lines of trenches and managed to hold off the Allied army. Dubbed the "Miracle of the Marne", the battle saved Paris, ended German hopes of a quick victory in the west.
First Battle of the Marne
