Even if they failed in the ambitious venture, the British could at least hope, beside continuing their policy of striking blow upon blow at the enemy, to make an end of the accursed Ypres Salient, and drive the Germans from the dominating semicircle of higher ground from which they had so long harassed our troops. Half of this task had indeed been accomplished by the Battle of Messines. The southern curve of the Salient had almost disappeared. It remained to cut away the northern. The great part of the fighting of Ypres, 1917, was to take place north of the Zonnebeke Road. The attack launched on July the 31st by the Fifth Army of General Gough, and the First French Army of General Anthoine on his left, met with a considerable measure of success. At its outset, indeed, the success appeared complete; but the Germans, holding their positions lightly and in depth, with the local counter-attack as one of the main weapons of defence, retook much of the ground won. The Pilkem spur was, however, in our hands. Great as had been our losses, the attack upon a position of tremendous strength had gone well enough for a beginning. But the weather, so pitiless on the Somme, that had almost startled pessimists by its unwonted mercy at Messines, broke that very day. Ere afternoon was over rain began to fall in torrents. By the following morning the ground, ploughed up by weeks of shell-fire, was a sea of mud. The 55th Division, in the fate of which the 36th Division was particularly interested, since its artillery was supporting the attack, and its other arms were to relieve their Lancashire comrades in that sector at a later date, had fared as well as any other. The troops had gone forward with great dash and had almost everywhere reached their final objective, known as the Green Line, east and just south of St. Julien. The leading battalions had, however, suffered very heavy loss from the fire of German machine-guns, distributed in depth, and had not been sufficiently strong to resist the counter-attack when it came. They were driven in upon the second objective, or Black Line, which followed, roughly speaking, the line of the road running south-east from St. Julien to the farm known as Pommern Castle, in the Pommern Redoubt.[39] It was an advance of fifteen hundred yards. To the south affairs had gone less well, and the Black Line remained to be taken.