The fighting during July and August had greatly weakened the enemy forces. All the most famous German units had appeared—the pick of the Bavarians, the 5th Brandenburgers, and every division of the Guard and Guard Reserve Corps. The time was ripe early in September for a new attack which should accelerate the enemy’s decline, and give the British front a new orientation. Haig’s immediate aim was to break through the German third line; but his ultimate objective was a thrust north-eastward across the Upper Ancre, so as to get behind the great slab of unbroken enemy positions from Thiepval northward. The moment was propitious for a new blow. The French on the British right had won conspicuous successes; Brussilov was still pinning down the Austro-German forces on the Eastern front; Sarrail had just launched an offensive in the Balkans; Rumania had entered the war, and was pouring troops into Transylvania; and the recent changes in the German High Command had for the time being slightly dislocated the machine. [Sidenote: _Sept. 15._] [Sidenote: _Sept. 25-26._] On Friday, 15th September, Haig struck from a point south-east of Thiepval to Ginchy, with a force the larger part of which, such as the Guards, the Canadians, and the New Zealanders, was fresh to the Somme area. He used for the first time the new British tanks, and in one day advanced to an average depth of a mile on a front of more than six, taking Courcelette, Martinpuich, and Flers. Only on his right, where the Guards were faced with an impossible task, was there any serious check. On 25th September he struck again between Combles and Martinpuich, and for the second time advanced one mile on a front of six, and took Morval, Lesbœufs, and Gueudecourt, while on the 26th the right wing of Sir Hubert Gough’s Fifth Army carried Thiepval and the whole of that crest. That evening the Allied fortunes in the West had never looked brighter. The enemy was now back in his fourth line, and had lost all the advantages of the higher ground. His _moral_ was seriously shaken, and it appeared as if his great machine was getting out of gear. If heaven granted a fine autumn there was good hope that a further advance might drive him from the Bapaume ridge and crumble his whole front between Arras and Péronne.