After the battle of Cambrai the Division went back into Corps reserve for a few days, and then moved north again into the area of the Fourth Army (General Sir H. S. Rawlinson). By the 12th of December units were concentrated some twenty to twenty-five miles south-west of Ypres, with Divisional Headquarters at Blaringhem. The Divisional Artillery, after a most trying march over roads coated with ice, arrived in this area on the 24th, when the Divisional Artillery Headquarters was opened at Robecq and the batteries went into billets in the neighbourhood of Haverskerque. On the 7th of January 1918 the 20th Division, less the artillery, relieved the 30th Division in the left sector of the IXth Corps front (Lieut.-General Sir A. Hamilton Gordon). The front line, 2700 yards in length, ran north-east and south-west for about an equal distance on either side of the Menin road, which it crossed north-west of Gheluvelt. The position lay on the forward slopes of the long ridge which overlooks Ypres from the south and east. From the high ground about Clapham Junction several marshy streams flow south and east, cutting the slopes of the ridge into a succession of spurs, on one of which the village of Gheluvelt stands. The defensive system included a series of lines which at this time were still in course of construction. Behind an outpost line lightly held ran the main defensive position in which the reserves of battalions were generally posted. Behind this again ran an Intermediate Line just below the crest of the ridge, a Corps Line, and an Army Line which extended from the ramparts of Ypres to the south. The ground along which the front trenches ran had been won as a result of the hard fighting in September and October 1917, since when British troops had twice attacked in the northern part of the sector with a view to improving their position. In the second attempt, on the 3rd of December, some progress was made in the face of heavy machine-gun fire, but only a temporary advantage was gained, as the Germans, attacking on the 14th under cover of a trench mortar barrage, recovered the greater part of their original line. In so doing they curtailed our observation and to a certain extent improved their own. It was this problem of observation that made it essential for us to yield no further ground, for should the enemy capture the front line here his view of our position would be improved very greatly. An official memorandum issued by the Fourth Army at this time states: “The area of the Army Battle Zone about the Menin road is probably the most important on the whole Army front, and it rests with the IXth Corps to make it as nearly impregnable as possible.” This, then, was one of the tasks which the Division had to undertake.