in the neighbourhood of the Ancre to become a pronounced and dangerous salient. Moreover, it was known that he was constructing a rearward line of defence, subsequently known as the Hindenburg Line, which would materially shorten his defensive front and thus release a number of divisions which could be moved into reserve.
Such was the position of affairs on Jan. 1 1917. The maintenance of pressure on the enemy on the Ancre-Somme battlefront was now of immediate importance. Signs were not lacking that the enemy had considerably weakened, and his position in the Ancre salient was vulnerable and dangerous. After a period of bad weather it became possible during Jan. to undertake minor and local operations, which resulted in the capture of the Beaumont Hamel spur, thus opening up a wide field of view and observation for artillery fire. No time was lost in making use of this advantage. Indeed, it was essential to engage the enemy closely, whether it was his intention to retire voluntarily to some previously prepared position, or whether his defence was involuntarily weakening. The country on both banks of the Ancre consists in pronounced undulations with spuxs running towards the stream from both north and south. Opportunity was offered for skill in the handling of comparatively small bodies of troops, in making use of the ground, and of cooperation both by movement and by fire. Making use of the tactical advantage obtained by possession of the Beaumont Hamel spur, the 6yd Div. carried out a successful operation early in Feb. which carried the British front forward on the N. bank of the river. This assisted towards the capture of a point on the S. bank, which gave observation into the upper valley of the Ancre and over the German gun positions. These hostile batteries which protected the Serre salient were forced to withdraw, thus weakening to a dangerous degree the German defences to the north. It was now possible to attack with advantage the Serre-Beauregard and Courcelette-Miraumont ridges, the possession of which, besides turning the German defences on the N. in the neighbourhood of Gommecourt and Monchy, would open up a further field of view up the valley of the Ancre, where many hostile batteries had been located. In order to gain this position an assault was delivered on the morning of Feb. 17 by the 2nd, 18th and 63rd Divs. on both banks of the stream. On the N. bank the attack was completely successful, while on the S. bank considerable resistance was encountered. Nevertheless, the whole position was occupied shortly afterwards, and small detachments and patrols working forward succeeded in occupying the enemy's defences on a wide front from opposite Guedecourt to Serre, including the villages of Warlencourt and Miraumont as well as the Beauregard spur.
It had become increasingly evident that the German defence was weakening, and their troops were being gradually withdrawn, the first indications being on a narrow front in the valley of the Ancre, but now on a more considerable scale. The prolonged period of exceptional frost following on a wet autumn had frozen the ground to a great depth. The thaw, however, began in the third week of Feb.; the roads, disintegrated by the frost, now broke up, and the area of the 1916 battlefield became a quagmire. On the other hand the conditions of the weather favoured the defenders, who fell back on to fresh unbroken ground, and the succession of misty days covered their movements.
Notwithstanding these difficulties the British and Australian troops kept up constant pressure, and by the delivery of minor attacks drove the enemy from position to position, until by the end of Feb. the whole of the Ancre valley and the higher ground to the N., including the village of Gommecourt, fell into their hands. The enemy had now evidently fallen back into a previously prepared line of defence the trench system known as the Le Transloy-Loupart line, cutting off the Ancre salient and covering the villages of Le Transloy, Grevillers, Achiet-le-Petit and Bucquoy. It was possible that he would make a stand on this defensive line. If not, undoubtedly his withdrawal would be conducted on a more comprehensive scale altogether and on a wider front.
Owing to the heavy work required to be executed in rendering the roads passable, and moving forward guns, ammunition and supplies, in addition to the necessity for gaining ground to within assaulting distance of this defensive system, a delay of a week occurred before operations of a more serious character could be undertaken. On March n and 12 the Le Transloy- Loupart line was subjected to so effective a bombardment that on the morning of the I3th the enemy abandoned this strong position. Grevillers and Loupart wood were immediately occupied, and preparations put in hand to attack the enemy's next line of defence, which covered Bapaume and Achiet-le-Grand.
For some time prior to this date indications had been ob- served of a further and wider extension of the German withdrawal. It had been ascertained that the Germans were preparing with feverish haste a new and powerful defensive system, the Hindenburg Line, which, branching off from the original defences near Arras, ran S. E. for 12 m. to Queant and thence passed W. of Cambrai in the direction of St. Quentin. The immediate object appeared to be to escape from the salient between Arras and Le Transloy, but it was also evident from the preparations the Germans were making on a grand scale, that they contemplated an eventual evacuation of the greater salient between Arras and the Aisne valley N.W. of Reims. The withdrawal to the Hindenburg defences would cause a very considerable contraction in the length of the line, with a consequent increase of the German reserves. It was evident that the Somme battles of 1916 had materially reduced his strength, and with the expected onslaughts on the western front, coupled with a Russian offensive on a grand scale, it was necessary for them to contract the front and conserve their strength.
Constant watch had accordingly been kept by the British along the whole front S. of Arras, strong patrols, kept alert and active, pushing forward here and there, with the result that St. Pierre Vast wood was occupied on March 16. Meanwhile in- formation was received which indicated the reduction of the enemy's forces S. of the Somme, and pointed to the probability that his line in that sector was being held by rear-guard detachments supported by machine-guns, whose withdrawal might be expected at any moment.
It was evident that the enemy was withdrawing according to a carefully prepared plan along the entire front of recent operations and on both banks of the river Somme. Orders were accordingly given by the British G.H.Q., in conjunction with the French, for a general advance on the morning of March 17. Except at certain localities where detachments of infantry and machine-guns had been left to cover his retreat, there was little serious resistance to the advance, and that resistance was rapidly overcome.
On March 17 Chaulnes was captured by the 6ist Div. and Bapaume by the 2nd Australian Div., while further to the right the French entered Roye. On the following and subsequent days the advance continued, and the whole intricate system of German defences in this area, consisting of many miles of powerful well-wired trenches which had been constructed with immense labour, passed into the hands of the Allies.
On March 18 the British 48th Div. gained the important tactical position of Peronne, and Mont St. Quentin which lies above it. The possession of this locality at the angle of the Somme showed clearly that the enemy would not stand on the line of the river, for it outflanked, that line to the south. The bridges over the Somme, which had been systematically destroyed, were temporarily and partially repaired with great rapidity, and the British troops, passing over, deployed into open country with patrols and cavalry thrown forward.
By this time the Allies' advance had reached a stage at which the increasing difficulty of maintaining the communications rendered it imperative to slacken the pace of the movement. Not only had the bridges over the river Somme been destroyed, and the roads rendered almost impassable both artificially and from the weather, but the wide belt of devastated ground over which the Somme battle had been fought offered immense difficulties to the passage of guns and transport. Moreover, in
