(the Belgian Army, the British Second Army and the French Sixth Army), attacked near Ypres in Flanders (the Fifth Battle of Ypres). Both attacks made good progress initially but were then slowed by supply difficulties. The Grand Offensive involved attacking over difficult terrain, resulting in the Hindenburg Line not being broken until 17 October. On 29 September, the central attack on the Hindenburg Line commenced, with the British Fourth Army (with British, Australian and American forces) attacking in the Battle of St Quentin Canal and the French First Army attacking fortifications outside St Quentin. By 5 October, the Allies had broken through the entire depth of the Hindenburg defences over a front. General Rawlinson wrote, "Had the Boche [Germans] not shown marked signs of deterioration during the past month, I should never have contemplated attacking the Hindenburg line. Had it been defended by the Germans of two years ago, it would certainly have been impregnable…." On 8 October, the First and Third British Armies broke through the Hindenburg Line at the Second Battle of Cambrai. This collapse forced the German High Command to accept that the war had to be ended. The evidence of failing German morale also convinced many Allied commanders and political leaders that the war could be ended in 1918; previously, all efforts had been concentrated on building up forces to mount a decisive attack in 1919. Subsequent operations Through October, the German armies retreated through the territory gained in 1914. The Allies pressed the Germans back toward the lateral railway line from Metz to Bruges, which had supplied the front in northern France and Belgium for much of the war. As the Allied armies reached this line, the Germans were forced to abandon increasingly large amounts of heavy equipment and supplies, further reducing their morale and capacity to resist. The Allied and German armies suffered many casualties. Rearguard actions were fought during the Pursuit to the Selle (9 October), battles of Courtrai (14 October), Mont-d'Origny (15 October), the Selle (17 October), Lys and Escaut (20 October) (including the subsidiary battles of the Lys and of the Escaut), the Serre (20 October), Valenciennes (1 November), the Sambre (including the Second Battle of Guise) (4 November), and Thiérache (4 November), and the Passage of the Grande Honnelle (5 November), with fighting continuing until the Armistice took effect at 11:00 on 11 November 1918. The last soldier to die