The decision of G.H.Q. on these questions was that the Channel Ports must be adequately defended at all costs, and that if any sector of the line must be left weakly defended, that sector must be in the southern area, which the Fifth Army had now taken over. The depth of the space available for retirement in rear of the lines in this area no doubt had its influence in this decision; and in addition, the fact that, in the event of a considerable withdrawal of our forces under the pressure of the German attack, a natural line of defence in rear of the forward positions seemed to be offered in the line of the Somme, which at Péronne makes a wide sweep southwards, thus forming a natural barrier more or less parallel with the British front in the St Quentin district. Possibly a further factor was the apparent natural strength of the extreme south of the front between Moy and La Fère, where the Oise Canal and marshes formed a wide and difficult obstacle between the Germans and our own troops. In the southern area, moreover, it would in case of need be more easy to make use quickly of such reserves as the French might be able to place at G.H.Q.'s disposal.
II. The Retreat from La Fère
The Fifth Army was allotted a front of 42 miles, which was held by 17 divisions in line and 3 infantry and 3 cavalry divisions in reserve. The sector was held by four Corps, from left to right the VII (Congreve), the XIX (Watts), the XVIII (Maxse), and the III (Butler).
The III Corps, with which alone we are concerned, comprised at the date of battle the 14th, 18th and 58th Divisions on a front of 30,000 yards, a gigantic sector for 27 battalions, not one of which was at war strength. In reserve were the 2nd and 3rd Cavalry Divisions. The sector allotted to the 58th Division, in which it relieved the 30th between the 7th and 9th February 1918, was the extreme right of the British Armies and extended from north of Travécy, where it touched the 18th Division on the left, to south of Barisis, where it linked up with the French on its right. This enormous front of nearly 9½ miles was held by two brigades, the two subsectors finding their natural division in the Oise marshes and the Canal de St Quentin, which at La Fère take a sudden turn westward, thus running at right angles into the British positions. North of the Canal the country is comparatively open and gently undulating, while south of it the lines plunge through the hilly and densely wooded district of the Forêt de St Gobain.
The marsh area at La Fère is about a mile and a half wide, so that the frontage which needed active defence by each Brigade was roughly four miles. On so vast a frontage a defence by continuous trench lines was clearly out of the question, and the British defence was designed to be in great depth. It was divided into three zones of defence. The Forward Zone, about 1000 yards in depth, relied for its defence on small company redoubts with the space between taken up by hidden machine-guns. This zone was intended to act as a "shock-absorber" in which the first intensity of the enemy's onslaught might be met and checked. The main defence was to be offered in the Battle Zone, about 1500 yards in rear of the Forward Zone. The Battle Zone occupied a depth of about 2000 yards and was to consist of isolated and wired forts, again strengthened by inter-supporting machine-guns. It was hoped that a final check might be administered to the enemy's attempts in this zone, but in rear of it a further defensive system, in this case a continuous line, was to be created as a Rear Zone. Beyond this again the Somme line was to be put into a state of defence.
At the date of taking over this area from the French the defensive organisation on the lines above indicated was practically non-existent. Very little depth was provided for in the defence and in rear of the Forward Zone practically all was yet to be done. The Battle Zone redoubts were inadequate and insufficiently wired, while the Rear Zone line was merely spit-locked.
For weeks, therefore, the whole energies of every available formation, infantry holding the line, engineers, pioneers and labour corps units from all parts of the world, were concentrated on the enormous task of converting the G.H.Q. scheme into a reality. Valuable time which could have been well spent in training the infantry in defensive measures and counter-attack, and in assimilating the new personnel which had been brought into battalions by the reorganisation of January, was inevitably devoted to entrenching and wiring work, wearying in itself and trying as only work done against time can become. All ranks, however, were sufficiently impressed by the need, and all were working with the zeal born of a grim determination to prove themselves equal to the demands which would be made upon them.
The 173rd Brigade moved forward to take over the left or north brigade sector on the 7th February. The 2/4th Battalion railed from Villers-Bretonneux to Appilly, whence it marched to billets at Quierzy on the south bank of the Oise. Here it was joined the following day by the transport which had moved by road. On the evening of the 8th the Battalion was attached temporarily to the 174th Brigade south of the Canal, and on the 9th moved to the Forward Zone, where it relieved the 7th Londons. As was to be expected from the conditions under which the line was held, the Battalion was now rather scattered, Headquarters and C and D Companies being stationed at Amigny-Rouy, while A and B Companies were at Sinceny and the stores and transport at Autreville. Enemy activity in this area was almost non-existent and the whole energies of the Battalion were devoted to entrenching work, which was carried out under Royal Engineer supervision. Large working parties, totalling on some occasions 12 officers and 400 other ranks, were called for daily for a variety of tasks to which the only relief was a periodical exchange of companies for bathing at Sinceny. On the 24th February the Battalion completed the Divisional relief and moved to the extremity of the British lines, where it relieved the 8th East Surreys, Headquarters, C and D Companies occupying Bernagousse Quarries, while A and B Companies were billeted in Pierremande. In this area the Battalion spent a few quiet days, occupied in strengthening the battle positions under the Royal Engineers. On the 27th it was relieved by the 7th Londons, and returned to the 173rd Brigade, going into Divisional reserve in rear of the northern brigade subsector. In this area the Battalion was again much split up, Headquarters, A and B Companies being at Viry Noureuil, and C and D Companies at Tergnier. This day the Battalion was joined by three more officers of the 2/1st Londons, 2/Lieuts. L. F. Wardle, C. B. Francis and C. W. Cumner.
The situation on the 173rd Brigade front during February had been remarkably quiet. The policy adopted had been purely defensive, and our artillery had shown but little activity. The distance separating the British lines from the enemy's and the nature of the terrain had rendered observation a matter of some difficulty; but the enemy's energies appeared to be devoted to strengthening his own defences of La Fère rather than to the preparation of an offensive operation. The general impression gained from the Brigade Intelligence Summary for this month is indeed that the idea of any attack being launched in the La Fère area was rather ridiculous, and that everyone was quite prepared to settle down at Fargniers for life. General Gough, however, as is well known, did not share this comfortable optimism, for almost a month earlier at a conference of his Corps Commanders at Catelet he had made what later proved to be an accurate forecast of the location of the German attack.
The Battalion's work during the three weeks immediately preceding the battle calls for little comment. After two days in Divisional reserve it moved forward to the Battle Zone, in which it relieved the 3rd Londons on the 2nd March, and this position it continued to hold until the offensive was launched, providing daily working parties for the improvement of the defences. The early days of March saw a slight increase of artillery and trench mortar activity on both sides, but the area was still comparatively quiet with but little outward indication of the storm which was shortly to burst over it.