The Battle of the Marne was a World War I battle fought from 7–12 September 1914. It resulted in an Allied victory against the German Army, the battle was the culmination of the German advance into France and pursuit of the Allied armies which followed the Battle of the Frontiers in August and had reached the eastern outskirts of Paris. The Battle of the Marne was a victory for the Allies, the Battle of the Frontiers is a general name for all the operations of the French armies from 7 August to 13 September. A series of encounter battles began between the German, French and Belgian armies on the German-French frontier and in southern Belgium on 4 August 1914, Liège was occupied by the Germans on 7 August. The first units of the British Expeditionary Force landed in France, the Battle of Mulhouse was the first French offensive of World War I. The French captured Mulhouse, until forced out by a German counter-attack on 11 August, on 12 August, the Battle of Haelen was fought by German and Belgian cavalry and infantry, resulting in a Belgian defensive success. The BEF completed its move of four divisions and a division to France on 16 August. The Belgian government withdrew from Brussels on 18 August, the main French offensive, the Battle of Lorraine, began with the Battles of Morhange and Sarrebourg advances by the First Army on Sarrebourg and the Second Army towards Morhange. Château-Salins near Morhange was captured on 17 August and Sarrebourg the next day, the German 6th and 7th Armies counter-attacked on 20 August, and the Second Army was forced back from Morhange and the First Army was repulsed at Sarrebourg. The German armies crossed the border and advanced on Nancy, but were stopped to the east of the city. The Belgian 4th Division, the part of the Belgian army not to retreat to the defensive lines around Antwerp, dug in to defend Namur. Further west, the French Fifth Army had concentrated on the Sambre by 20 August, facing north on either side of Charleroi and east towards Namur, additional support was given to the Belgians at Namur by the French 45th Infantry Brigade. On the left, the Cavalry Corps of General Sordet linked up with the BEF at Mons, to the south, the French retook Mulhouse on 19 August and then withdrew. By 20 August, a German counter-offensive in Lorraine had begun, an offensive by the French Third and Fourth Armies through the Ardennes began on 20 August in support of the French invasion of Lorraine. The opposing armies met in thick fog, the French mistook the German troops for screening forces, on 22 August, the Battle of the Ardennes began with French attacks, which were costly to both sides and forced the French into a disorderly retreat late on 23 August. The Third Army recoiled towards Verdun, pursued by the 5th Army, Mulhouse was recaptured again by German forces and the Battle of the Meuse, caused a temporary halt of the German advance. At the Battle of Mons, the BEF attempted to hold the line of the Mons–Condé Canal against the advancing German 1st Army. The British were eventually forced to withdraw due to being outnumbered by the Germans and the retreat of the French Fifth Army
German soldiers (wearing distinctive pickelhaube helmets with cloth covers) on the front line at the First Battle of the Marne.
German and Allied positions, 23 August – 5 September 1914
French infantry charge, 1914
Opposing positions: 5 September (dashed line) 13 September (black line)