These three battles, Ourcq, Coulommiers, and Montmirail, constitute the recoil from Paris, and at the same time they constitute the defeat of what was hereinbefore shown to be one of the four fundamentals of the great German campaign plan. With the situation thus cleared, so to speak, one may now pass to the details of the second part of the German plan, which was to engage the powerful Ninth and Fourth Armies, under the command of Generals Foch and Langle, respectively, to break through them, if possible, but at all hazards to keep them sufficiently menaced to disable General Joffre from sending reenforcements therefrom to the army of General Sarrail, on which the whole force of the army of the crown prince was to be hurled.
The next section of the Allied armies, then, was General Foch's Ninth Army, which encountered the German drive at Fère Champenoise, and which resulted in the severe handling of General von Bülow's forces. With characteristic perception of the difference between a greater and a lesser encounter, General Foch called his share of the battles of the Marne, the "Affair of the Marshes of St. Gond." This did not culminate until Wednesday, September 9, 1914, so that the German retreat there was one day later than the final retreat of General von Kluck.
The clash between the armies of General von Bülow and of General Foch began, as did the battle wrath along the whole front, at dawn of that fateful Sunday, September 5, 1914. General Foch, a well-known writer on strategy, had devised his army for defense. He was well supplied with the famous 75-millimeter guns, holding them massed in the center of his line. His extreme right and left were mobile and thrown partly forward to feel the attack of the invading army. But, in spite of all preparations, General Foch found himself hard-set to hold his own on September 5, 6, 7, and 8, 1914. The battle continued incessantly, by night as well as by day, for the artillerists had found each other's range. There was comparatively little hand-to-hand fighting at this point, General Foch only once being successful in luring the Germans to within close firing range. The results were withering, and General von Bülow did not attempt it a second time. There seems reason to believe that General von Bülow had counted upon acting as a reserve force to General von Kluck during the latter's advance, and that, consequently, he did not think it prudent to risk heavy loss of life until he knew the situation to westward of him. There was some sharp "bomb" work at Fère Champenoise on September 8, and then came the night of the 8th.
It will be remembered that at the close of the battle of Montmirail on the evening of September 8, 1914, the western flank of Von Bülow's army had been exposed by the advance of General d'Espérey and the retreat of General von Kluck. Information of this reached Foch, and despite the danger of the maneuver, he thrust out his mobile left like a great tongue. That night the weather turned stormy, facilitating this move. At one o'clock in the morning, the statement has been made, word reached General Foch indirectly that air patrols had observed a gap in the alignment of the German armies between General von Bülow's left and General von Hausen's right.
During the darkness and the rain, therefore, General Foch had worked two complete surprises on General von Bülow. He had enveloped the German commander's right flank, and was safely ensconced there with General d'Espérey's army behind him, since the latter had by now advanced to Montmirail. At the same time he had thrust a wedge between Von Bülow and General von Hausen, threatening General von Bülow's left flank as well. The first was a seizure of an opportunity, executed with military promptness, the second was a bold coup, and its risk might well have appalled a less experienced general.
Considering the westernmost of these movements first, it will be seen at once how the enveloping action brought about the "Affair of the Marshes of St. Gond." General von Bülow's army was stretched in an arc around the marshes, which, it will be remembered, have been described as a pocket of clay, low-lying lands mainly reclaimed, but which become miry during heavy rains. It was General von Bülow's misfortune, that, on the very night that his flank was exposed, there should come a torrential downpour. These same marshes had figured more than once before in France's military history, and General Foch, as a master strategist, was determined that they should serve again. When the rain came, he thanked his lucky stars and acted on the instant.
When the morning of September 9, 1914, dawned, the left wing of General Foch's army was not only covering the exposed flank of General von Bülow's forces, but parts of it were two miles to the rear. Under the driving rain, morning broke slowly, and almost before a sodden and rain-soaked world could awake to the fact that day had come, General Foch had nipped the rear of the flank of the opposing army, and was bending the arc in upon itself. Under normal circumstances, such an action would tend but to strengthen the army thus attacked, since it brings all parts of the army into closer communication. But General Foch knew that the disadvantages of the ground would more than compensate for this, since the two horns of General von Bülow's army could not combine without crossing those marshes, now boggy enough, and growing boggier every second. The task was harder than General Foch anticipated, for the same rainy conditions that provided a pitfall for the Germans were also a manifest hindrance to the rapid execution of military maneuvers. But, in spite of all difficulties, by evening of that day, the flank broke and gave way, and two entire corps from General von Bülow's right were precipitated into the marshes. Forty guns were taken—to that time the largest capture of artillery made by the Allies—and a number of prisoners. Hundreds perished miserably, but General Foch held back his artillery from an indiscriminate slaughter of men made helpless in the slimy mud. Thus ended the "Affair of the Marshes of St. Gond," which broke still further the German right wing.
Thanks to General Foch's further activities, General von Bülow had troubles upon his left wing. When dawn of this same day or torrential rain, September 9, 1914, broke over the hill-road that runs from Mareuil to Fère-Champenoise, at which point lay the left of General von Bülow's army, it witnessed a number of 75-millimeter guns on selected gun sites commanding the right flank of the German right center. General Foch's daring, the success of the maneuver, and the fact that the conduct of all the French armies on that day and the day following seems to be with the full cognizance of this venture, led inevitably to the conclusion that those brilliant feats, conceived by General Foch, had been communicated to General Joffre in time for the French General Staff to direct the French armies to the right and left of General Foch to cooperate with his action. Had General Foch been less ably supported, his wedge might have proved a weak salient open to attack on both sides. But General Foch's main army to the west kept General von Bülow busy, and General Langle's army to the east fought too stubbornly for the Duke of Württemberg to dare detach any forces for the relief of General von Bülow. General von Hausen's Saxon Army was weak, at best.
What were the forces that operated to make this particular point so weak are not generally known. As, however, the divisions from Alsace were much in evidence three or four days later, it is more than probable that these divisions were intended for service at this point, and also to reenforce General von Kluck's army, but that, by the quick offensive assumed by General Joffre on the Ourcq, and, owing to the roundabout nature of the German means of communication, these expected reenforcements had not arrived. The German official dispatches point out that General von Bülow's retreat was necessitated by the retreat of General von Kluck. Of this there is no doubt, but even military necessity does not quite explain why General von Bülow bolted so precipitately. His losses were fearful, and the offensive of General Foch rendered it necessary for the Germans to fall back on the Aisne.
The armies of the Duke of Württemberg and of the crown prince may be considered together, for they were combined in an effort to pierce the French line near the angle at Bar-le-Duc. General Langle held on desperately against the repeated attacks of the Duke of Württemberg. Ground was lost and recovered, lost again and recovered, and every trifling vantage point of ground was fought for with a bitter intensity. Though active, with all the other armies, on September 5 and 6, 1914, it was not until September 7 that General Langle found himself strained to his utmost nerve. If he could hold, he could do no more, and when night fell on September 7, no person was more relieved than General Langle. Yet the next day was even worse. Instead of slackening in the evil weather, the German drive became more furious. The exhausted Fourth Army fought as though in a hideous nightmare, defended their lines in a sullen obstinacy that seemed almost stuporous, and countercharged in a blind frenzy that approached to delirium. It was doubtful if General Langle's army could hold out much longer. But, when General von Bülow was compelled to retreat, when General Foch turned his attention to General von Hausen's Saxon Army, and when General Joffre found himself in a position to rush reenforcements and reserves to the aid of General Langle, a new color was given to the affair. The defense stiffened, and as rapidly as it stiffened, so much the more did it become patent that the Duke of Württemberg could not afford to be in an exposed position far in advance of all the other attacking armies. Wednesday, September 9, 1914, revealed to the German center the need of falling back on the crown prince's army, which was the pivot on which the whole campaign swung.