The Battle of Marne began on September 6th 1914. The battle lasted a total of 6 days. This was the first battle of World War 1.
The German army would march through Belgium and into France. This being called the Schlieffen Plan. The first German army was told to double back and support the 2 German army from attacks. The first would soon be attacked by the french.
The military governor of Paris, General Joseph-Simon Gallieni, had convinced the french commander to send him an army. Once the French attacked the Germans they forced them back and the Germans dug trenches to hide in. This started the concept, trench warfare.
The battle was at its highest point of the German advance into France and pursuit of the allied armies which followed the battle of the Frontiers in August, which had reached the Eastern outskirts of Paris.
The counter attack of French armies and British strong force along the Marne river forced the German Imperial Army to draw back from Paris and retreat.