First Battle of the Marne

Also called: Miracle of the Marne

French and British troops stopped the German army, which had swept through Belgium almost to Paris, on the river Marne. Germany’s plan for a short war collapsed and the Western Front froze into trench warfare.

To avoid a war on two fronts, Germany planned to defeat France in a few weeks by marching through neutral Belgium, then turn east before Russia could fully mobilize (the Schlieffen Plan). In August 1914 the German armies crossed Belgium and came within a few dozen kilometres of Paris.

But when the German First Army wheeled east of Paris and exposed its flank, the French under Joffre and the British Expeditionary Force counter-attacked from 5 September, even using Paris taxis to rush troops forward. From 9 September the Germans fell back to the Aisne.

With its short-war plan in ruins, Germany faced a long struggle on two fronts. As each side tried to outflank the other, they dug a line of trenches from the North Sea to the Swiss border, and for nearly four years the Western Front barely moved.