Sir Douglas Haig in his despatch[2] divides the battle of the Somme into three phases. In the first, which ended with this advance on the 14th-18th of July, the success of the attacks evidently came as a surprise to the enemy, who must have considered his defences practically impregnable. The second phase was a severe struggle for the possession of the main ridge, ending with the capture of Guillemont and Ginchy on the 3rd and 9th of September respectively. By this time the enemy had begun to bring strong reinforcements on to the scene, so that on the 18th of July, at the close of the first phase, his 62 battalions had been increased to 138, and by the end of August, when the 20th Division came into the fighting, his original 6 divisions on the front of attack had been reinforced by 30 divisions more.[3] The third phase was the exploitation of the success. The line gained by the 18th of July, at the close of the first phase, included Trônes Wood, Delville Wood, and Longueval; it then turned to the west, passing on the north side of Bazentin-le-Grand and Bazentin-le-Petit to join our original trenches near Ovillers-le-Boisselle. This left a dangerously sharp salient about Longueval and Delville Wood, overlooked by the enemy all round from the south-east to the north-west. Behind this salient ran the French communications as well as our own, and many guns and much ammunition had here to be crowded into a confined space. It was evident that the enemy might well cause us heavy loss by bringing concentrated artillery fire to bear on this area, while if he could drive in the salient he would get direct observation over the ground behind. Indeed, in a heavy counter attack on the 18th he succeeded in regaining part of Delville Wood and penetrated into the northern half of Longueval, maintaining these gains until on the 27th and 29th he was once more driven back. It became particularly important, therefore, in this struggle for the ridge, to straighten out the line by the capture of Guillemont and Leuze Wood, so bringing the right flank of the attack into line with the centre. With this end in view, while a further advance was being made in the north towards High Wood and Pozières, several attacks were made on Guillemont. The first, on the 23rd of July, failed. On the 30th of July, and again on the 8th of August, our troops entered the village but were unable to hold it. Lastly, on the 16th and 18th of August, attacks planned on a more comprehensive scale advanced the line to Guillemont station and to within a few hundred yards of the outskirts of the village, which, however, still remained in German hands.[4]