By these operations General Mangin wrested from the Germans at Cuts and Mont de Choissy all the heights remaining south of the Oise in that region. The French batteries now commanded a wide sweep of territory and most of the important roads. General Mangin's right, firmly established on the heights around Fontenoy, now began to drive the enemy from the elevated ground south of the Oise, leaving them no option but to cross the river, or retreat toward the east. The Germans fought desperately to hold their ground, relying principally on their vast number of machine guns. During the night, in anticipation of General Mangin's attacks, they had received reenforcements brought up from the Soissons front in motor lorries to help meet the shock of the French troops. They fought with dogged determination, but from the start their position was hopeless. Their artillery fire was of the feeblest and they had practically no help from airplanes. Continuing their attacks in the region northwest of Soissons, General Mangin's troops captured Lassigny. The advance, made over a front of fifteen miles, smashed the German lines at some points to the depth of five miles. To the southeast of Lassigny, by winning a foothold in Plemont, the French menaced the Germans' grip on the valley of Divette. Across the Oise and farther east, Mangin's men had reached the river from the south between Sempigny and Pontoise. In the conquered territory, won in less than twenty-four hours, the Germans were driven from twenty villages. While the French were driving the Germans before them and winning wide stretches of territory, the Third British Army under General Sir Julian Byng was adding to the glory of British arms. Under cover of a heavy fog, General Byng attacked on a ten-mile front from the Ancre River to the neighborhood of Moyenville, driving back the enemy along the whole line and gaining at some points ground to the depth of two miles. General von Below's Seventeenth Army, which the British fought against, was badly cut up; their losses in guns and men were so heavy as to suggest that the German morale was crumbling, and that their fighting power was rapidly disintegrating.