Marne, battle of the, two important battles of World War I that are named for the Marne River. In the first battle (Sept. 6-9, 1914) the German advance on Paris was halted at the Marne by the Allies under Joffre, Gallieni, and Sir John French. The German retreat that followed signified the abandonment of the Schlieffen plan (see under Schlieffen, Alfred, Graf von). In the second battle (July, 1918) the last great German offensive was decisively repulsed by the Allies.