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.
It was just at daybreak that the British big guns began the overture that preceded the attack. The fog was so dense that the men in the tanks could not see more than a hundred feet ahead, but it was favorable to the assaulting formations as it served to shield their movements from the enemy observers. The German guns replied only feebly, showing that they were short of heavy cannon, a fact that had been noted before in recent fighting in this region. Their chief dependence on this occasion was in machine guns, with which they seemed to be exceedingly supplied. Situated in isolated posts, these did effective work, and there was sharp fighting at various points. The German garrison occupying the shell-shattered ruins of what had been the village of Courcelles, near the center of the battle front, made a stubborn resistance, and for a time the advance of the British infantry was held up at this point. With the arrival on the scene of a drove of tanks, German resistance broke down. The machine-gun nests were quickly smashed, and the gunners killed or made prisoners; and wherever there was resistance the tanks quickly crushed out all desire of the enemy to continue the fight.
Engaged in this advance were tanks of various types, and all found their work cut out for them. The big tanks smashed in the enemy defenses, dipped in and out of shell holes and performed all the heavy work, while the small whippet tanks and armored cars dashed around at high speed attacking gun nests from the rear and clearing the way for the advance of the infantry. Despite the vigorous resistance offered by the Germans at some points, the British losses in casualties were comparatively small, and some formations met with none at all. The village of Beaucourt was won with only three casualties.
When the fog lifted about noon, and the sun shone out, the Germans attempted several counterattacks, but were unable to force the British to relinquish a foot of the territory they had gained.
In the morning of August 22, 1918, the British delivered a new attack on a six-mile front between Albert and Bray on the Somme, which was entirely successful, all objectives being won and an advance made of two miles. The important town of Albert was captured and 1,400 prisoners and a large number of cannon. North of the Ancre the battle raged throughout the day, and the Germans were forced to fall back all along the line. Isolated counterattacks were attempted, but they crumbled beneath the hammer blows of the British armies. There was hard fighting along the Arras-Albert railway embankment for the valuable positions that overlook the flat country around. To the south from Achiet-le-Grand to the Ancre the opposing armies swept back and forth in attacks and counterattacks again and again renewed. At Achiet-le-Grand and Miraumont, where the Germans launched their most ambitious counterattacks, they employed fresh troops that had been rushed forward from other sectors to relieve Von Below's hard-pressed Seventeenth Army.
During August 21-22, 1918, the French Third and Fourth Armies under General Mangin continued to press their advance night and day along the front from Lassigny to the north of Soissons. At some points an advance of seven miles was made, and there was evidence that the Germans were so badly mauled that their retreat amounted practically to a rout.
The French push toward the roads leading to Chauny menaced the enemy's line of retirement and explained his hurried retreat. By the capture of Bouguignon, St. Paul-aux-Bois, and Quincy the French had won command of the valley of the Ailette from the region of Coucy-le-Château to the Oise. General Humbert's troops also made notable gains and wrested important positions from the enemy. By the occupation of the height of Plemont and the capture of Thiescourt the French now held all the hills known as the Thiescourt Massif, thus giving them the strongest points overlooking the region around.
It was evident in different parts of the fighting area that the Germans were in a confused and even panic-stricken state of mind. The French advance guard was so close to them when they crossed the Oise that they had not time to destroy the bridges over the river. Allied observers noted streams of enemy transports in wild confusion back of the fighting front, and all discipline and order seemed to have been lost. Upon the Ailette front the sudden attack of the French caused the hasty retreat of a division of German reserves which had been brought forward to launch a counterattack. Falling back, this division precipitated a panic in the ranks of another division which had intended to support the first division's attack, and the result was a confused and disorderly retreat.
Marshal Foch's plan to give the enemy no rest day or night, and to follow up each blow by another, a plan which had resulted in great victories for the Allies and constant demoralization of the forces of the enemy, continued to be the order of the day. The British, operating on a thirty-mile front, unceasingly hammered Crown Prince Rupprecht's armies, striking suddenly at different points, and always advancing in spite of the most determined opposition. The Third and Fourth British Armies under Generals Byng and Rawlinson made important gains on August 22-23, 1918. It was a day of disaster for the Germans, whose desperate attempts to check the British advance resulted only in frightful losses of men and accomplished nothing. Prince Rupprecht sacrificed his troops recklessly in an effort to stave off the inevitable. The British guns swept the Germans from the field, or crushed them as they tried to force their way forward. One entire German battalion was annihilated during the fighting. General Byng made an advance of two miles to the neighborhood of Grandcourt, east of the Ancre. Gomiecourt and four other villages were carried by storm. To the north the British captured Achiet-le-Grand, which is on the Arras-Albert railroad, and for the possession of which Germans and British had been fighting for some days past.