Within the same later weeks of September General Joffre had been able to throw against the German flank from Noyon to the Somme the powerful French army commanded by General Castleneau. He was thus in a position to forestall the German design. On the other side German army corps had by extraordinary forced marches arrived from Belgium just in time to ward off the thrust of this French army against Laon, a thrust which would have crippled the whole German defence and a thrust which the battle of the Aisne was fought to assist. The fighting from Noyon to the Somme was deadly. On the German side losses were not regarded. The purpose of these troops was, cost what it might, to hold the ground until the main reinforcements came up. They suffered appalling losses. Nevertheless, though at a heavy sacrifice of life, the immediate objective, that of preventing a French advance along the valley of the Oise, was accomplished. The German resistance was undoubtedly very brave. To begin with, thanks alike to the superiority of their artillery, and to the _élan_ of their recent victory, the French advanced with some rapidity. The Germans were driven out of Compiègne. Their hastily thrown-up trenches were found filled with dead, many slain by the terrible concussion of the French high explosive shells. As the French advanced these trenches were filled in. Meanwhile, packed into every available train and by every available railway, the masses of the new German formations were being rushed westward. Immediately they detrained they were hurried into the fighting line. In the face of these increasing numbers the French advance along the valley of the Oise was held. From the defensive the Germans passed at once to the counter-offensive. In great strength they launched an attack from Noyon and towards Roye. The front swayed. In the end, however, the French line from the Oise to the Somme remained firm. It must then have been seen that the German outflanking scheme, thus anticipated, had become, on the lines first laid down, impracticable. The result was the great attack on Rheims. It is clear now that when the attack was decided upon, the Germans believed the army of General Castleneau to consist not of fresh troops, but of the reserve of the main French army. Acting upon that belief they concluded that a vigorous assault upon Rheims ought to be successful. If successful the assault would accomplish all that the outflanking scheme promised. In any event it would prevent the French from massing further forces to the north of the Somme. With the German reinforcements still coming forward, the outflanking scheme could be tried again at the point where the French line at that time ended. The attack upon Rheims failed because the German hypothesis upon which the attack had been founded was in fact false. The army of General Castleneau _did_ consist of fresh troops, and _not_ of the reserves of the main French army.