The Twenty-third Division relieved the First and were in turn relieved by the Fifteenth in this sector, which faced the Switch Trench and Martinpuich. The Switch Line was exposed to a very heavy fire for several days, at the end of which it was attacked by this famous division, the same in number at least as that which had left nearly two-thirds of its rank and file upon the bloody slopes of Hill 70. On August 12 the advance was carried out with great dash: the 45th Brigade upon the left and the 46th upon the right. The attack was only partially successful, and the 46th Brigade was held up through the fact that the Germans had themselves been in the act of attack, so that the trenches were very strongly held. The operations continued, however, and the initial gains were enlarged, until upon August 20 the whole Switch Line fell and was permanently consolidated.
Leaving this left sector we must turn to the Thirty-third Division on its right, two battalions of which had got forward on July 15, as far as the line of the road connecting High Wood with Little Bazentin. The right flank of the Highland Light Infantry had been held up by fire from this wood, and in the evening the 91st Brigade of the Seventh Division had evacuated the southern edge of the wood in order to allow of bombardment. That was the position on the night of July 15.
The line of the road was held all night, and early next morning the advance was ordered upon the German Switch Trench in front. It was hoped that the wood had been cleared during the night, but in the morning the Highlanders found themselves still galled by the continual fire upon their right. It was clear that the attack could not go forward with such an impediment upon the flank—one more instance of a brigade being held up by a handful of concealed men. It was hoped that the enemy had been silenced, and the attack was made, but no sooner had it developed than a murderous fire burst from the wood, making it impossible for the Highlanders to get along farther than the road. The 1st Queen's, however, being farther from the wood were able to get on to the Switch Trench, but found it heavily wired and stiff with men. Such a battalion does not take "No" easily, and their colonel, with a large proportion of their officers and men, was stretched in front of the fatal wire before it became evident that further perseverance would mean destruction. The 16th Rifles and half the 2nd Worcesters, the remaining battalions of the 100th Brigade, were brought up, but no further advance was possible until the wire could be cut by the guns. About four in the afternoon of July 16 the remains of the brigade were back in the road from which they had started. The attack had failed, partly from the enfilade fire of High Wood, partly from the impassable wire.
The 98th Brigade was on the left of the 100th, filling up the gap to Bazentin village. They had extended their right in order to help their sorely-tried comrades, and they had themselves advanced upon the line of the Switch Trench—the 1st Middlesex leading, with the 4th Suffolk in support. The 2nd Argyll and Sutherlands with the 4th King's Liverpool were in reserve. They got well forward, but ceased their advance when it was found that no progress could be made upon the right. Thus, for the time, the division was brought to a stand. That night the 19th Brigade relieved the 100th, which had been very hard hit in this action. After the change the 1st Scottish Rifles and the 20th Royal Fusiliers formed the front line of the 19th Brigade, the Rifles in touch with the 22nd Brigade of the 7th upon their right, while the Fusiliers were in touch with the 98th Brigade upon their left.
The general situation did not admit of an immediate attack, and the Germans took advantage of the pause to strengthen and slightly to advance their position. On July 17 the hard-worked Twenty-first Division upon the left was drawn out, and both the Thirty-third and Seventh had to extend their fronts. On the other hand, the First Division came in upon the left and occupied a portion of the Bazentin-le-Petit Wood. The position at that time was roughly that the Seventh Division covered the front from High Wood to Bazentin Grand, the Thirty-third Division from Bazentin Grand to Bazentin Petit, and the First was from their left to Pozières.
Upon July 18 there was a very heavy German attack upon Delville Wood, which is treated elsewhere. This was accompanied by a severe barrage fire upon the Bazentins and upon Mametz Wood, which continued all day. That night the Nineteenth Division came into line, taking over Bazentin Petit, both village and wood. The Thirty-third Division moved to the right and took some pressure off the Seventh, which had done such long and arduous service. These incessant changes may seem wearisome to the reader, but without a careful record of them the operations would become chaos to any one who endeavoured to follow them in detail. It is to be emphasised that though divisions continually changed, the corps to which they temporarily belonged did not change, or only at long intervals, so that when you are within its area you can always rely upon it that in this particular case Horne of the Fifteenth Corps is the actual brain which has the immediate control of the battle.
As the pressure upon Congreve's Thirteenth Corps on the right at Delville Wood and elsewhere was considerable, it was now deemed advisable to attack strongly by the Fifteenth Corps. The units for attack were the Thirty-third Division upon the left, and the depleted Seventh upon their right. There was to be no attack upon the left of the Thirty-third Division, but the 56th Brigade of the Nineteenth Division was handed over to the 33rd Division to strengthen the force. The objectives to be attacked were once again High Wood (Bois des Foureaux), Switch Trench, and the connecting trench between them. The Seventh Division attacked east of the wood on the line between it and Delville Wood.
The assault upon High Wood was assigned to the 19th Brigade. The 2nd Worcesters of the 98th Brigade were pushed out so as to cover the left flank of the assaulting column. At 2 A.M. of July 20 the two advance battalions of stormers, the 5th Scottish Rifles on the right, the 1st Scottish Rifles upon the left, were formed up in open ground outside the British wire. Preceded by scouts, they went silently forward through the gloom until they approached the south-western edge of the wood. A terrific bombardment was going on, and even those stout northern hearts might have quailed at the unknown dangers of that darksome wood, lit from moment to moment by the red glare of the shells. As the barrage lifted, the wave of infantry rushed forward, the 5th Scottish Rifles making for the eastern edge, while the 1st Regular Battalion pushed on in the endeavour to win through and secure the northern edge.
It was speedily found that the tenacious enemy had by no means loosened his grip of the wood. A portion of the Switch Trench runs through it, and this was strongly held, a line of spirting flames amid the shadow of the shattered trees. Machine-guns and wire were everywhere. None the less, the dour Scots stuck to their point, though the wood was littered with their dead. Both to east and to north they slowly pushed their way onwards to their objectives. It was a contest of iron wills, and every yard won was paid for in blood. By 9 o'clock the whole of the southern half of the wood had been cleared, the leading troops being helped by the 20th Fusiliers, who followed behind them, clearing up the lurking Germans. At that hour the northern end of the wood was still strongly held by the enemy, while the stormers had become much disorganised through loss of officers and through the utter confusion and disintegration which a night attack through a wood must necessarily entail.
The remaining battalion of the 19th Brigade, the 2nd Welsh Fusiliers, was, at this critical moment, thrown into the fight. A heavy barrage was falling, and considerable losses were met with before the wood was entered; but the Fusiliers went forward with splendid steadiness and dash, their colonel taking entire local command. In the early afternoon, having got abreast of the exhausted Scottish Rifles, who had been under the hottest fire for nearly twelve hours, the Welsh attacked the north end of the wood, their advance being preceded by a continuous fire from our Stokes mortars, that portable heavy artillery which has served us so well. The enemy was still unabashed, but the advance was irresistible, and by 7 P.M. the British were for a time in possession of the whole of the blood-sodden plantation. It was a splendid passage of arms, in which every devilry which an obstinate and ingenious defence could command was overcome by the inexorable British infantry. The grim pertinacity of the Scots who stood that long night of terror, and the dash of the Welsh who carried on the wave when it was at the ebb, were equally fine; and solid, too, was the work of the public school lads of the 20th Fusiliers, who gleaned behind the line. So terrific was the shell-fire of the disappointed Germans upon the north end of the wood, that it was impossible to hold it; but the southern part was consolidated by the 18th Middlesex Pioneer Battalion and by the 11th Company Royal Engineers.