Since Le Cateau, the little British Army had played only a secondary part; it was now to have the honour of saving the left wing of the Allies for the third time. From the moment it began to recross the Marne, solidly extended by d’Espérey, its intervention became a conclusive factor. It must have been during the morning of the 9th that the German Grand Staff reconciled itself to the necessity of a general retreat, at least from Senlis as far east as Fère Champènoise. In after years, when the simple art of entrenchment had been elaborated and the men had become incredibly hardened to shell-fire, these same wooded hillsides would be contested foot by foot. At this time, freer and larger movements were required, especially when no considerable aid could be expected, when supplies were short, and the danger appeared on two sides. Kluck’s very persistence, not having attained any positive result, told against him. His men might be persuaded that this was “not a retreat, but only a regrouping of forces for strategic reasons”;[71] all officers but the youngest knew that the “smashing blow” had been broken, the famous enveloping movement had failed, a new plan of campaign must be thought out. For that, rest must be found upon a naturally strong defensive position such as the line of the Aisne and the Laon mountains. By noon on September 9——a gloomy, showery day——the call was urgent. The I Army could do no more. Its ammunition was nearly exhausted. Its best units were physically and morally broken. It had no longer the strength to bury its dead——they were unclothed and cast upon great pyres of straw and wood; and the odour of burning flesh added a new horror to the eastern part of the battlefield. Kluck’s advance from Nanteuil and Betz, during the morning, was only a diversion, a last blow to secure liberty of movement. At 11 a.m., the French found Betz evacuated; Nanteuil and Etavigny were still held. Whipped on by Headquarters, General Boëlle’s two divisions of the 4th Corps crept forward again. During the afternoon, aviators observed long enemy convoys, followed by troop columns of all arms, crowding all the roads from the Ourcq to the Aisne. For several critical hours they were screened by a vigorous defence of the centre lines east of Etrepilly and Puisieux. This and a slight reaction near Nanteuil were the final spasms of the battle of the Ourcq. We have seen that Marwitz, beaten by the 1st British Corps at Montreuil-aux-Lions, 13 miles due east of Etrepilly, in the early afternoon, had gone back to the Clignon, and that the whole angle of the Marne and Ourcq had been evacuated. Kluck could flatter himself to have held out to the last possible moment. Gradually the remainder of his artillery was removed from the Trocy plateau; and, under cover of night, all but rearguards made off to the north-east. The 6th Army seems to have been too weary to discover the flight of its redoubtable foe until daybreak on the following morning.