The 16th Infantry Brigade attacked on a battalion front--one company of the Bedfords bombing up the trench from Leuze Wood, and the remainder over the open to the north against the south-west face. The Buffs and York and Lancasters supported the attack, but in spite of the greatest gallantry could not take the Strong Point.
The 1st Leicesters and the Norfolks, passing through the entrenched Foresters and Suffolks, attacked the Quadrilateral from the north-west with equal drive, but they too failed. Some ground, however, was made, and by 10 a.m. the 16th Infantry Brigade on the south, and the 71st Infantry Brigade on the north, were digging in close to the enemy's wire and trenches.
During the day constant reports arrived that the Guards had gained their objectives, and that tanks and cheering men were moving through Lesboeufs. It was not until the following morning that this report was proved to be incorrect, and that it was Flers which had been captured. In the meantime it appeared to the Divisional G.O.C. (General Ross) that the prospect of a break-through on a large scale was prejudiced solely by the repulse of the 6th Division. He therefore ordered a night attack on the flanks of the Quadrilateral to be executed by two battalions of the 18th Infantry Brigade (Brig.-Gen. R. J. Bridgford). These battalions, the 2nd Durham Light Infantry and the 11th Essex, moved round after dark and attacked; the former from the north, the latter from the south-east to the left of the 16th Infantry Brigade. The 11th Essex lost direction, while the 2nd D.L.I. bombed down a trench only to find that it did not lead into the Strong Point. Except on the 6th Divisional front and at High Wood, which was captured during the night, the whole line had advanced, and it was a bitter blow to the Division to think that their sacrifices had been in vain.
On the night of the 16/17th September the 18th Infantry Brigade relieved the sorely-tried 71st Infantry Brigade, and fresh preparations were made for an attack, on the 18th, of the Quadrilateral, which had been strongly reinforced by the enemy through the sunken road.
The K.S.L.I. dug themselves in with their left on the railway, so as to assault the south-west face of the Strong Point. The weather having cleared, the trenches were now carefully located from the air and heavily bombarded, and on the 18th September, under both a stationary and creeping barrage, and with the York and Lancasters bombing up the trench from Leuze Wood, and the 18th Infantry Brigade (West Yorks and 14th Durham Light Infantry) attacking the north-west face and the trench running north from the Quadrilateral, this redoubtable Strong Point was at last captured with comparatively small loss after what must be conceded as a magnificent defence, and which had cost the Division upwards of 3,500 casualties. Nine machine-guns and 160 unwounded prisoners were taken in the Quadrilateral and many Germans killed.