Meanwhile the 10th R.B. on the right had deployed on the line south of Les Rues Vertes; their right flank was exposed, as the 12th Division was still behind the Bonavis-Masnières road and the two troops of the Northumberland Yeomanry filled up this gap. Later, touch was gained with the 12th Division.
The 10th K.R.R.C. moved forward along the La Vacquerie valley, with two companies on each side of the road. All went well on the right, but the left companies were troubled by machine-gun fire from the north. A patrol sent out in this direction discovered the enemy holding a strong point, which was vigorously attacked and captured with some 200 prisoners. The battalion then took up a position in a sunken road 1500 yards south-west of Les Rues Vertes, sending one company in the afternoon to relieve the yeomanry on the right of the 10th R.B.
The 11th K.R.R.C. in reserve moved forward to a position close in rear of the 10th K.R.R.C.
The 61st and 60th Brigades were consolidating their objective across the north-eastern end of Welsh Ridge, and the 59th Brigade occupied the line running south from Les Rues Vertes. The 12th Division held the second objective from the right of the 61st Brigade to Lateau Wood inclusive, with a line running forward from there to the right of the 59th Brigade. The 6th Division, on the left of the 60th Brigade, had pushed through Ribécourt and thrown out a defensive flank along the high ground north and north-west of Marcoing, where it was in touch with the left of the 29th Division. The right flank of the 29th was then working through Masnières. The 51st Division was on the outskirts of Flesquières and the 62nd and 36th Divisions were advancing further to the north and north-west. Divisional Headquarters moved forward at this time to Villers Plouich.
By 9 P.M. the 10th R.B. on the right and the 11th R.B. on the left had pushed forward along the spur and were established between Les Rues des Vignes and the canal south of Mon Plaisir Farm. One company, under Capt. Ashwell, occupied part of the village of Les Rues des Vignes after severe opposition.
During the afternoon considerable advance was made on the left, where the 52nd Division penetrated as far as Anneux, over two miles north of Flesquières, although the latter still remained in the hands of the enemy. The British line, therefore, formed a salient between Lateau Wood and Marcoing, divided from the very sharp salient at Anneux by the re-entrant at Flesquières. It had been impossible to get the guns forward along the sunken roads quickly enough to support the infantry fighting at Masnières and Marcoing, but the two factors which most limited the results of the battle as a whole on this day were the check at Flesquières and the absence of a large force of cavalry on the far side of the canal. These factors, and the consequent inability of the 29th Division to push forward north and east of Masnières, allowed the Germans to occupy the Beaurevoir-Masnières line which ran in front of Rumilly and Crèvecœur. From this position the Germans were able to command the line of the 59th Brigade. On the 21st Flesquières was captured and the line straightened, and further advance was made towards the north.
On the night of the 20th/21st the 11th R.B. were ordered to seize the crossings at Crèvecœur to allow French cavalry to pass through at dawn. The night was pitch dark, the men were exhausted, and Crèvecœur was found by then to have been occupied by the enemy. The battalion captured an enemy machine gun complete with team, but was unable to take the bridges. That night IIIrd Corps issued orders that every effort must be made to gain possession of the Beaurevoir-Masnières line and to capture Crèvecœur. The rôle of the Division was to push on to Crèvecœur in conjunction with the 29th Division on the left. The 59th Brigade was detailed to carry out this operation, with the assistance of twelve tanks, and zero was fixed at 11 A.M. on the 21st. Later, the attack of the 29th Division was cancelled. The tanks ran out of petrol, and eventually at 2 P.M. the 11th K.R.R.C., the assaulting battalion of the 59th Brigade, had to attack alone. The battalion came under enfilade fire from Rumilly and the high ground north of the canal, so that in spite of several efforts to force a passage during the day, little progress was made. That night the 11th K.R.R.C. consolidated a position on the spur north-west of Les Rues Vignes, while a company of the 11th R.B. held the bridge-head below the village. This company, owing to heavy casualties and to the impossibility of obtaining reinforcements, was ordered to withdraw during the night. Before doing so, the remains of the company, assisted by the R.E., made four gallant but unsuccessful attempts to destroy the bridge.
The 11th R.B. formed a defensive left flank, covering the crossings south and south-east of Mon Plaisir Farm.
Two batteries of the 92nd Field Artillery Brigade moved forward at daybreak to positions north-west of Lateau Wood and supported this attack under considerable shell-fire. In the evening they withdrew to a small re-entrant between Lateau Wood and the La Vacquerie—Masnières road, where they were joined by the rest of the brigade.
The medical arrangements for the battle included an A.D.S. and a walking wounded collecting post at Gouzeaucourt, and advanced posts near Villers Plouich and on the Gouzeaucourt—Bonavis road just behind the front fine. After the attack other posts were pushed forward to the La Vacquerie valley, towards Marcoing and later to Les Rues Vertes. Wounded from many different divisions passed through the A.D.S. at Gouzeaucourt. Excellent work was done by the bearers of the Division under Lieut.-Colonel A. C. Osburn, commanding the 60th Field Ambulance.