The third stage of the battle therefore opened with hopes which even the experience of the second had not been able to quench. Gough's Fifth Army had since early in July been formed as an independent command to the left of Rawlinson's Fourth, and its right comprised the 1st Canadian Corps which was to attack Courcelette. The other points of the German third line of defence were Martinpuich, Flers, Lesboeufs, and Morval. Martinpuich was the objective of a Scottish division of the New Army, Flers that of the New Zealanders, Lesboeufs and Morval those of the Guards and another division of the old Regulars. Behind the British lines were collected twenty-four "Tanks," which were to precede them in the attack and prove by this first experiment their value as a weapon of war. On the 14th a brigade of Gough's army stormed the Hohenzollern trench and a redoubt called by the Germans a wunderwerk; apart from this success, the attack diverted German attention from the real offensive, which began on the 15th with an intense bombardment. The Tanks spread terror and devastation among the German lines and the results of the day for once exceeded all expectations. Courcelette fell to the Canadians, Martinpuich to the Scots, Flers to the New Zealanders. High wood was at last enveloped in this advance, and Delville wood passed by the division of the New Army which pushed from Ginchy towards Lesboeufs. That effort on our right was, however, hampered by the Germans in the Quadrilateral and Bouleaux wood to the east of Ginchy, and the Guards were unable to carry out the most important tactical part of the day's work by carrying Lesboeufs and Morval. The French had no such accumulation of gains on the 15th, but they conquered a larger area between the 13th and 18th. They began on the 13th with the bold capture of Bouchavesnes right across the great road from Péronne to Bapaume, and supplemented it by taking Le Priez farm on the flank of Combles. On the 17th they completed their work in Berny and Vermandovillers south of the Somme, and on the 18th added Deniécourt. On that day the British at last mastered the Quadrilateral east of Ginchy, and thus prepared for the great success which attended the next general attack on the 25th. It was the best day of the whole campaign. Lesboeufs and Morval fell on the north of Combles, while the French took Rancourt on the south-east, and away to the west Gough's army made the surprising seizure of Thiepval. Further fruits were gathered on the morrow; Gueudecourt, which had been taken but abandoned on the 25th, was recovered; the French who had then failed against Frégicourt now took it; and Combles was the prize of their joint success. Then the weather broke; and the Germans, who had already begun to prepare their Hindenburg lines far away in their rear, were enabled to cling to the Bapaume salient until they had taken all the precautions for an orderly and inexpensive retreat.