Second Battle of the Marne | World War I

Through World War I, the Second Battle of the Marne (15 July – 6 August 1918) was Germany's last major Western Front assault. The attack was thwarted when an Allied counteroffensive, backed by hundreds of tanks, overpowered the Germans on their right flank, causing heavy fatalities. The German setback signaled the start of the relentless Allied push, which ended with Germany signing an armistice 100 days later.

After the failure of Germany's spring offensive to finish the war, Chief Quartermaster General Erich Ludendorff believed that an attack through Flanders would give Germany a decisive victory over the British Expeditionary Force (BEF). Ludendorff planned a massive diversionary operation along the Marne to hide his aims and divert Allied troops away from Belgium.

On July 15, 23 German divisions from the First and Third armies, led by Bruno von Mudra and Karl von Einem, attacked the French Fourth Army, led by Henri Gouraud, east of Reims. The French Fourth Army had the 42nd Division of the United States attached to it. Meanwhile, 17 divisions of the German Seventh Army, led by Max von Boehn, attacked the French Sixth Army, led by Jean Degoutte, to the west of Reims, aided by the Ninth Army, led by Johannes von Eben (the Battle of the Mountain of Reims). Ludendorff planned to divide and conquer the French. To counter an intensive bombardment and infiltrating soldiers, the French Fourth Army had constructed a defense in depth east of Reims. Their main line of defense was four to five kilometers behind the front line, beyond the range of enemy field guns. It was a continuous trench line excavated on a reverse slope to avoid being overlooked by enemy artillery observers on the ground, and it was dug to prevent infiltration. Two lines of solid points, usually on reverse slopes, ran between the front and the main line of resistance. Although aerial observers did discover a concentration of field guns behind the main line of resistance, the Germans could not detect its weakness from the rate of firing because the French gun line behind the front was sparsely handled. German assault tactics emphasized surprise, but French intelligence based on aerial observation provided a clear warning. They discovered the hour for the attack from twenty-seven prisoners captured in a trench raid. The German bombardment was set to begin at 12:10 p.m. At 11:30 a.m., the French opened fire on the German assault trenches, undermining the attackers' confidence. When the Germans started the fire, they battered the nearly deserted French front line, and their counter-battery fire hit several unoccupied gun positions. The attackers breezed through the French front and were then driven further by a rolling barrage, which was soon well ahead of the soldiers, who were slowed by areas of resistance. They were ordered to rest, reorganize, and wait until their field guns were put into range when they came across the French railway. They attacked the mainline around 8:30 a.m. the following morning, an hour later than they had planned. The bulk of the French artillery was able to stop them with precise fire. They attempted again at midday but were unsuccessful. The German commanders were concerned that they could not win after a French counter-attack gained little progress. The Fourth Army could now deploy reinforcements to its western counterparts, who had fared less well. On the opening day of the assault, the defenders of the south bank of the Marne in France west had to endure a three-hour bombardment that included numerous gas shells. Under this cover, Stormtroopers flooded the river in a variety of vehicles, including 30-man canvas boats and rafts. Under fire from the Allied survivors, they began erecting skeleton bridges at 12 locations. Despite the aerial intervention of 225 French bombers dropping 44 short tons of bom, the Germans had captured a bridgehead on either side of Dormans 4 mi deep and nine mi (14 km) wide by evening. The German advance was halted on July 17, 1918, when the French were reinforced by the British XXII Corps and 85,000 American troops.

The failure of the Germans to break through or destroy Allied armies in the field allowed Ferdinand Foch, the Allied Supreme Commander, to launch the planned major counteroffensive on July 18th, with 24 French divisions under French command, including the American 92nd and 93rd Infantry Divisions. To oppose the German attack, the Allies needed to be well prepared. The Allies were thought to have a thorough knowledge of the German offensive's goals and capabilities. The Allies were up to date on every detail of the German strategy. Engineer Cpt. Hunter Grant, with the help of engagement coordinator and engineer Cpt. Page created a fraudulent scheme, according to mythology. Handcuffed and placed in a vehicle that appeared to have run off the road at a German-controlled bridge with a briefcase containing bogus plans for an American counter-attack, a man who had died of pneumonia was handcuffed and placed in a vehicle that appeared to have run off the road at a German-controlled bridge. The Germans altered their attack to oppose the phoney Allied plan after discovering and being duped by these preparations.

As a result, the French and American forces led by Foch were able to launch a separate attack on enemy lines that were exposed, forcing the Germans to retreat. This battle signalled the start of a German retreat that was never effectively reversed. Nine American divisions (totalling 243,000 troops) joined four French divisions to drive the Germans out of the St. Mihiel salient in September. Foch had previously identified vulnerabilities in the German offensives in May. The force that defeated the German attack was primarily French, backing the United States, the United Kingdom, and Italy. Because Foch had to cooperate with so many people, coordinating this counter-attack would be a tremendous challenge. "Despite having four national commanders, he has no real ability to issue orders in his name. They'd have to battle as a unified army, overcoming the major challenges of disparate languages, cultures, doctrines, and combat styles." The advent of new American troops, untroubled by years of war, significantly boosted Allied resistance to the German advance. "I never seen men charge to their death with more spirit," Floyd Gibbons wrote about the American forces. During a German assault on their trenches on July 19, the Italian Corps lost 9,334 officers and men out of a total combat strength of around 24,000, successfully preventing the German advance. Henri Mathias Berthelot rushed the 51st (Highland) and 62nd (West Riding) British infantry divisions, as well as the Italians, down the Ardre Valley (the Battle of Tardenois– called after the adjacent Tardenois plain). On the 20th of July, the Germans ordered a retreat and were forced to return to launching their Spring Offensive. They fortified their flank positions against the Allied pincers, and Ludendorff ordered a line from the upper Ourcq to Marfaux on the 22nd. Allied assaults were costly and yielded little. The Germans had withdrawn their centre behind Fère-en-Tardenois and built an alternate rail link by July 27. In the west, the Germans kept Soissons. The offensive was resumed on 1 August by French and British divisions of General Charles Mangin's Tenth Army, which advanced to a depth of over 5 miles (8.0 km). In the face of German counteroffensives, the Allied counteroffensive stalled on August 6. The salient had been diminished by this point, and the Germans had been forced to retreat to a line along the Aisne and Vesle Rivers; the front had been cut by 28 miles (45 km).

The Allies were victorious in the Second Battle of the Marne by a large margin. The baton of a French Marshal was presented to Ferdinand Foch. The Allies had captured 29,367 German prisoners, 793 pieces of artillery, and 3,000 machine guns while killing 168,000 Germans. The strategic advances on the Marne signified the end of a streak of German victories and the start of a sequence of Allied victories that would conclude the war in three months.