The Second Battle of the Marne (Seconde Bataille de la Marne; 15 – 18 July 1918) was the last major German offensive on the Western Front during the First World War. The attack failed when an Allied counterattack, supported by several hundreds of tanks, overwhelmed the Germans on their right flank, inflicting severe casualties. The German defeat marked the start of the relentless Allied advance which culminated in the Armistice with Germany about 100 days later.
Following the failure of the German spring offensive to end the conflict, Erich Ludendorff, Chief Quartermaster General, believed that an attack through Flanders would give Germany a decisive victory over the British Expeditionary Force (BEF). To shield his intentions and draw Allied troops away from Belgium, Ludendorff planned for a large diversionary attack along the Marne.
The battle began on 15 July when 23 German divisions of the First and Third armies – led by Bruno von Mu