Second Battle of the Marne

The Second Battle of the Marne is one of the major turning points of the First World War. After a massive German attack launched on 15 July to attempt to envelop Reims and drive toward Paris, French and Allied forces, well prepared, halted the enemy momentum. A major counter-attack began on 18 July, led by French, American, and British troops. The German offensive was broken and the Allies regained the initiative along the entire Western Front.

Since spring 1918, Germany had attempted a series of offensives to break the Allies before the massive arrival of American troops. Operation Friedensturm (Marne offensive) aimed to break through between Reims and Épernay, creating a pincer effect to encircle French forces to the east. But Foch, having become supreme commander of the Allied armies, anticipated the attack. Troops were ready, positions well fortified, and aviation mobilised. This time, the Allies intended not only to defend but also to counter-attack.

Germany committed its best divisions, supported by massive bombardment and coordinated attacks on both banks of the Marne. However, the Allies had perfected their tactics: defence in depth, rolling barrage fire, and coordinated use of aviation and mobile artillery enabled the blocking of the advance. On 18 July, Foch launched a surprise counter-offensive from Villers-Cotterêts, with French, American, and British divisions supported by more than 300 tanks. This manoeuvre broke the German flank. Within a few days, troops recaptured Château-Thierry and Soissons, and drove the Germans back beyond the Vesle.

The German defeat on the Marne signalled the end of all offensive capacity of the imperial army. The initiative definitively shifted to the Allies. German morale collapsed and desertions increased. On the Allied side, the effectiveness of unified command under Foch was demonstrated, as was the growing strength of American forces. This victory prepared the great offensives of summer and autumn (the Hundred Days Offensive). The Second Marne is perceived as the revenge of the 1914 battle, and became a symbol of the turning point in the war.