The Battle of Marne took place between 5th of September to the 12th of September 1914.
The outcome was a victory for the Allied forces which ended a long month of German offensive.
The German Army was successful in the early part of World War One and it was widely expected that Paris would be taken by the Germans as most of the British forces had to retreat back towards the Marne river.
French and British field armies counterattacked the German imperial Army forcing the Germans to withdraw its push into Paris and retreat to the North East. This set the stage for 4 years of trench warfare on the Western Front.