First Battle of the Marne
The First Battle of the Marne was a WW1 military engagement between the Imperial German Army and the Franco-British forces. It took place on the Marne River, France, from September 6 to September 12, 1914. This battle was an important Allied (Entente) victory as the French and British armies managed to stop the powerful German offensive through Belgium, which had been conceived in the Schlieffen Plan. It was also important from a tactical point of view, as it forced first the Germans and then the Allies to dug in and build long deep trenches, marking the end of the mobile war and the demise the cavalry.
Summary
Having defeated the Belgian Army and taken their forts at the Battle of Liege on August 16, the German forces continued their march towards Paris. In Lorraine and the Ardennes, the French Army and the British Expeditionary Forces tried to halt this offensive but the Germans defeated them at the Battle of the Frontiers in late August, forcing them to fall back towards the French capital to prevent it from being taken by the powerful enemy. However, the French commanders, Joseph Joffre and Joseph Gallieni ordered their troops to counterattack along the Marne River, asking the British commander, Sir John French, to do the same.
It took three French armies and the BEF to stop the enemy in their tracks, pushing them back. By September 11, the German 1st and 2nd Army had been forced to retreat towards the Aisne River, where they dug in and waited for the Franco-British forces' counter attack. That military clash would take place in the First Battle of the Aisne.
Opposing Forces
Entente: French 5th (General Franchet D'Esperey), 6th (General Maunoury), and 9th Army (General Foch). British Expeditionary Force (Sir John French).
Germans: 1st (Obst von Kluck), 2nd (von Bülow), and 3rd Army (Freiherr von Hausen).
Below, an infantry company from the French 5th Army attacking across the rolling landscape at the Germans near the the town of Conde-en-Brie, during the First Battle of the Marne.