The long frost had now been succeeded by a remarkably sudden thaw which created conditions of marked discomfort in the trenches. The water pent up in the soil for so long filled all the trenches to a depth of about two feet, and the trench walls everywhere began to fall in, throwing an enormous amount of work on the occupying battalions in keeping them in a defensible condition.
By night our patrols continued their activities, but each night on approaching the enemy's lines were met with brisk machine-gun fire, which showed increasing activity each day. The Battalion observers also reported daily columns of smoke in rear of the enemy's lines, arising, as was found subsequently, from the systematic orgy of destruction in which the Germans indulged prior to their retirement. There was, moreover, during these few days a very marked increase of shelling in our back areas, the villages of Pommier, Berles, Bretencourt and Bailleulmont all receiving an unusually large amount of heavy fire.
The 11th proved to be the most disturbed day of this tour of duty, the enemy being exceedingly active in machine-gun and trench mortar fire. About 100 light shells, of which many were gas, fell in Bienvillers, fortunately without inflicting loss on the Battalion. On the 12th the 2/4th Londons were relieved by the 2/1st Londons and moved in Brigade reserve to Pommier, where they continued training. The XVIII Corps Commander inspected the Battalion on the 16th.
The Battalion Orderly Room now began to be inundated by the Brigade Intelligence Staff with plans, maps and all kinds of collated information as to the villages which would lie in the line of the Division's expected advance. All preparations were made for an immediate move. Units in reserve were held in instant readiness to advance, their first line transport wagons standing ready packed.
The night of the 16th/17th March was unusually quiet, and patrols pushed out by the 2/1st Londons about daybreak on the 17th returned with the information that the German trenches about Monchy were deserted. A patrol sent forward from the 2/4th Battalion under Capt. Bottomley was able to penetrate into Monchy itself and returned about midday with the definite assurance that the village was evacuated.
The same day the order was given for a general advance of the whole of the British forces from Arras to Roye.
That afternoon the 173rd Brigade moved forward, the 2/1st Londons occupying the German front line at Monchy and some high ground south of the village, while the 2/4th Battalion was brought forward from Brigade reserve, "leap-frogging" through the leading Battalion to the German trenches east of the village. A Company pushed ahead and reached a point about 300 yards west of Adinfer Wood. Here the Battalion was in touch with the 6th South Staffords on the right. North of Monchy village the 2/2nd Londons continued the line with the 174th Brigade on their left.
The withdrawal of the Germans from the Monchy Salient involved a continual shortening of our lines as the salient became straightened out, and in order to effect this the 2/1st Londons were withdrawn on the night of the 17th to Pommier, while the 2/4th Battalion continued its advance, "squeezing-out" the 2/2nd Londons as it pushed forward. By 5 p.m. the following day it had reached a position near Rabbit Wood, a small copse on the North side of Adinfer Wood, its left being now in touch with the 175th Brigade while the 46th Division kept pace with its advance on the right.
At midnight on the 18th/19th March the 2/4th Londons were withdrawn in Brigade reserve to Ransart, which village was now occupied by Brigade Headquarters. A few hours later, at 4.30 a.m. on the 19th, the 2/1st Londons once more took up the advance towards Boiry-Becquerelle.