First Battle of The Marne - Causes

Causes

The first month of the First World War had resulted in a series of victories by German forces in France and Belgium. By the end of August 1914, the whole Allied army on the Western Front had been forced into a general retreat back towards Paris. Meanwhile, the two main German armies that had just conquered Belgium continued to advance through France. It seemed that Paris would be taken as both the French Army and the British Expeditionary Force fell back towards the Marne River.

British troops had suffered heavy casualties during the German attack into France. Field Marshal Sir John French, commander of the British Expeditionary Force (BEF), blamed his heavy losses on French vacillation and uncoordinated French withdrawals. In particular, he blamed French General Lanrezac, commander of the French Fifth Army, for Lanrezac's failure to fight and unannounced pullbacks, though these had effectively saved the French Fifth Army from defeat. Lanrezac, in turn, was furious with Field Marshal French for his refusal to support the Fifth Army at Guise-St. Quentin.

Relations between the British commander and the French commanders suffered greatly. Field Marshal French made plans to move all British troops back from the front along their lines of communication for rest and reorganisation. French Commander-In-Chief Joseph Joffre persuaded the British War Secretary, Herbert Kitchener, to intervene, and Kitchener met personally with Field Marshal French. Kitchener told Field Marshal French that a withdrawal by the British would be disastrous for both the French and British. Field Marshal French agreed to keep British troops on the front line as long as their flanks were not exposed by French withdrawals.

As the German First and Second Armies approached Paris, they began to swerve to the south-east away from Paris in an attempt to envelop the retreating French armies, exposing their right flank to the allies. By 3 September, Joffre had become aware of the German armies' tactical error. On 4 September, he made plans to halt the French and British withdrawal and attack the Germans all along the front with the French Sixth Army (150,000 men) and the aid of the British Expeditionary Force (70,000 men) under the command of Sir John French (who was prompted to join this attack by the British war minister, Lord Kitchener). The attack was set to begin on the morning of 6 September. However, General Alexander von Kluck, the commander of the German First Army, detected the approach of the Allied forces on 5 September and, too late, began to wheel his Army to face the west. On the morning of 5 September, battle commenced when the advancing French Sixth Army came into contact with cavalry patrols from General Hans H. K. Gronau's IV Reserve Corps on the right flank of the German First Army near the Ourcq River. Seizing the initiative in the early afternoon, Gronau's two divisions attacked with light artillery and infantry into the gathering Sixth Army and pushed it back into a defensive posture before the planned allied assault for the following day, but the threat to the French offensive by Kluck's wheeled First Army in this preliminary Battle of the Ourcq (French: Bataille de l'Ourcq) ignored the allied forces advancing against his right flank, and was later reduced both by the arrival of the taxicab reinforcements from Paris and orders for Kluck to retreat to the Aisne River, delivered by Moltke's staff officer, Oberstleutnant Richard Hentsch.