The leading units of the Division left Amesbury on the 20th July. The route followed was either by Folkestone and Boulogne or by Southampton and Havre, and then by train from the ports of disembarkation to the area west of St Omer. The various stages of the journey—embarking men and horses, entraining and detraining in France, marches to rest camps and billets—were all accomplished satisfactorily if not without some discomfort, chiefly due to the rough and rainy weather. On the 22nd Divisional Headquarters was established at Lumbres, and the Division was concentrated in this area by the 26th.
The next day orders came for a further move eastwards, and on the 28th the Division started on a hot and trying march into the area of the IIIrd Corps (Lieut.-General Sir W. P. Pulteney), which formed part of the First Army and which was holding a line between Neuve Chapelle and Armentières.
By the 30th the various units had moved into billets in the area bounded roughly by the line Hazebrouck—Bailleul—Steenwerck—Neuf Berquin, with Divisional Headquarters at Merris.
The situation on the British front at this time was briefly as follows:—
The Third Army under Sir Charles Munro held the right of the line from the Somme, where it was in touch with the French, to a point south of Arras. Between this point and Grenay (four miles north-west of Lens) the French Tenth Army intervened, cutting off the Third Army from the First, which, under Sir Douglas Haig, continued the line to near Armentières; north again, Sir Herbert Plumer’s Second Army held the left of the British line as far as the right of the French troops at Boesinghe.
The IIIrd Corps, consisting now of the 8th, 27th and 20th Divisions, was in touch on the right with the Indian Corps near Fauquissart; thence the line ran in a general north-easterly direction parallel to the Rue Tilleloy and some 200 to 500 yards on the south-east side of it, until, opposite Picantin, it turned east for about a mile. North of Rouge Banes it began to turn north-east again, and kept this general direction, passing close in front of La Cordonnerie Farm, La Boutillerie and Rue du Bois to a point on the Armentières-Lille road about half a mile north-west of Wez Macquart.
LAVENTIE, 1915. Sketch A.
The 20th Division, like other troops in England, had been trained largely with a view to open warfare, so that on its arrival in France schools and courses of instruction had to be organised to carry on the training in trench warfare and in those forms of fighting that had lately come into use. Thus bombing was started almost at once, and the instruction given was thorough. Officers and N.C.O.’s went to the 8th and 27th Divisions for a course of training; bombing schools were opened in the Division, and brigade and battalion bombing officers appointed. Brigade bombing officers at the end of each course picked out any men who were likely to become really expert and kept them for a further course. The rest went back to their battalions as battalion or company bombers. The training was carried on under some difficulty at first, as nothing was provided. No bombs were available for instructional purposes, and therefore they had to be improvised. Machine-gun classes were also formed, and from time to time officers and N.C.O.’s went to Wisques for a course in the use of machine guns in the field. Gas-mask drill was very strict, and was practised every day. Demonstrations and lectures were given, and as many men as possible were made to pass through gas. In addition to these special courses of instruction, ordinary training was carried out.
Between the 2nd and the 17th of August all units, from brigade headquarters downwards, were attached to the 8th and 27th Divisions in the line, thus introducing officers and men to the realities of trench warfare.