The third part of the battle of the Marne, called by some the Battle of Montmirail, was not marked by special incident. General d'Esperey's part was to hold firm, and this he did. Not only by reason of the British assistance on the left, but also because the strong army of General Foch to the right was a new army, of greater strength than was known to General von Moltke and the German General Staff. The battle of Montmirail was won by the steady resistance of the Fifth Army to the hammer blows of the German right, and to the quick advantage seized by General d'Esperey when the British weakened the flank of the force opposing him. On September 8, 1914, General d'Esperey had not only held his ground, but had driven General von Kluck back across the Grand Morin River at La Ferte-Gaucher, and also across the Petit Morin at Montmirail. Since the British had butted the Germans back from the Petit Morin at La Tretoire, these three days of fighting in the battles of Coulommiers and Montmirail had won the Allies advanced positions across two rivers, and had so weakened the German right that it was compelled to fall back on the main army and forego its important strategic advantage on the east bank of the Ourcq River. 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 Fere Champenoise, and which resulted in the severe handling of General von Buelow'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.