In the afternoon of 5th September 1916 the 3rd Brigade relieved the 1st Brigade in the line in front of Bazentin le Grand. Their dispositions were 1 SWB left and 2 R MUN FUS right forward battalions, 1 GLOUC in support and 2 WELCH in reserve. The 2nd Brigade moved into support and the 1st Brigade back into reserve. To the left of 3rd Brigade was the 44th Brigade from the 15th (Scottish) Division and to the right was the 165th (Liverpool) Brigade from the 55th (West Lancashire) Division.
During the night of 5th/6th September 1916 the enemy artillery was fairly quiet and 2 WELCH and 1 GLOUC spent the night digging trenches. 2 WELCH worked on trenches in High Wood and 1 GLOUC on trenches to the west of the wood and dug an extension about 150 yards long running north east to a depth of 3 feet. The day was fairly quiet until about 19.00 hrs when the 165th (Liverpool) Brigade attacked a strong point on their left. The artillery fired supporting this attack brought a response from the enemy and some of this fell upon 2 R MUN FUS. The digging by 2 WELCH in High Wood and by 1 GLOUC west of High Wood was the principle work carried out through the night and 1 GLOUC also provided carrying parties.
Thursday, 7th September 1916 was a fine day and the 2nd Battalion, the King's Royal Rifle Corps [2 KRRC] and the 2nd Battalion, the Royal Sussex Regiment [2 R SUSS] from 2nd Brigade relieved 2 R MUN FUS in the left half of the 3rd Brigade's front. 2 KRRC took over the left hand end of the line and 2 R SUSS were next to them on the right. On relief a company of the 2 R MUN FUS relieved the right hand company of 1 SWB, the remaining companies of 2 R MUN FUS moving back to billets in the western edge of Mametz Wood. Brigadier-General Davies remained responsible for the whole front with 2 KRRC and 2 R SUSS coming under his command. During the night of the 7th/8th work continued on the trench parallel to High Wood and jumping off places were prepared in front of this trench.
2 WELCH moved up from reserve in Mametz Wood during the morning of Friday, 8th September 1916 and relieved 1 SWB and the company from 2 R MUN FUS in High Wood. The company of 2 R MUN FUS moved back to rejoin their battalion and 1 SWB occupied the southern end of the new extension running parallel to the wood. At midday the 2nd Brigade headquarters staff arrived and took over responsibility for the eastern part of High Wood being held by 2 KRRC and 2 R SUSS.
At the same time 1 GLOUC began to move forward to take up positions of assembly in the northern end of the new extension and Fife Trench. As they were moving into position short shooting by their own artillery smashed in parts of the trench which they were about to occupy causing a number of casualties. This prevented their fourth company from getting into positions of assembly as there was not enough room in the trenches.
The western edge of High Wood had been bombarded by the British artillery throughout the 7th and 8th September 1916 with the intention of cutting the wire. At noon on the 8th this changed to a slow continuous bombardment of the enemy trenches which continued until 17.30 hrs. An intense half hour bombardment by 2-inch mortars followed and at 18.00 hrs on Friday, 8th September 1916 the 3rd Brigade launched its attack as the Field guns shelled the enemy 200 yards to their front before lifting to the eastern side of High Wood and the north to fix the enemy in place.
1 GLOUC attacked on the left of the attack from their assembly positions in the northern end of the new extension against the enemy inside the western edge of High Wood. 1 company of the 1 SWB was attached to them for this attack. 2 WELCH attacked on the right advancing from the southern end of the extension against the enemy immediately to their front. The remainder of 1 SWB was in support. The 9th (Service) Battalion, the Royal Highlanders (Black Watch) [9 BLACK WATCH] of the 44th Brigade in 15th (Scottish) Division attacked in cooperation with the 3rd Brigade on the left of 1 GLOUC.
The infantrymen of the 3rd brigade left their trenches at zero hour.
1 GLOUC advanced to the edge of the wood and killed most of the enemy they found there. They then pushed onwards into the wood. The German trenches in the area had been obliterated and the enemy were found to be occupying shell holes in small groups. These had to be cleared one-by-one and after some vicious fighting, which took a heavy toll, Lieutenant Colonel Pagan and the remnants of his battalion reached their final objective.
1 SWB who were in support of them moved forward behind the 1 GLOUC and pushed through the forward edge of the wood. They were, however, held up by fire and unable to reinforce Lieutenant colonel Pagan's men who at 19.30 hrs were forced to withdraw. 1 SWB withdrew at the same time as 1 GLOUC.
The right hand assaulting company of 2 WELCH gained their objective without too much trouble. Their left hand assaulting company, however, was unable to make any progress due to the machine gun fire coming from the north of the wood and rifle fire from the enemy trenches directly to their front. 1 SWB in support tried to bomb up the trench that was holding left of 2 WELCH up, but their supply of bombs ran out as their carrying party was unable to get to them.
The Germans then counterattacked vigorously and the positions gained became untenable and by 20.00 hrs the left hand company was back where it had started. The right hand company of 2 WELCH still held onto its gains. However, the attack of 9 BLACK WATCH to the left was also forced backwards and this left both flanks exposed. Attempts were made to reinforce the men of 2 WELCH still holding on, but this proved impossible and at 04.00 hrs on 9th September 1916 they too withdrew to the trenches from which they had begun the attack.
Following the failed attack the 1 GLOUC minus two companies withdrew during the night to billets in Quadrangle Trench. The two companies remained in the line covering Fife Trench between High Wood and its junction with the New Trench.
2 R MUN FUS moved forward at 08.00 hrs and relieved the 2 WELCH, 1 SWB and the 2 platoons of 1 GLOUC still in the line. The 1 SWB moved back into billets along the western edge of Mametz Wood, while the 2 platoons of 1 GLOUC rejoined their battalion in billets in Quadrangle Trench and the 2 WELCH moved back to occupy the positions along the northern edge of Mametz Wood they had previously held. The one company of 2 R MUN FUS, that was holding the line at the eastern edge of the wood, was relieved around noon on 9th September 1916 by the 1 NORTH'N. They then rejoined their battalion and once again came under control of their own CO.
At 16.45 hrs on Sunday, 9th September 1916 the 2nd Brigade attacked Wood Lane and High Wood in conjunction with 2 R MUN FUS. The attack also failed and in the early morning 2 R MUN FUS were relieved by 1 L N LAN and the 2nd Brigade assumed responsibility for the whole 1st Division sector at 09.00 hrs on 10th September 1916. The 3rd Brigade's headquarters moved back to join their battalions in the vicinity of Mametz Wood and later that day they were relieved by the 141st (5th London) Brigade from the 47th (2nd London) Division. The 3rd Brigade then moved back to Henencourt Wood.