Failing to shift the enemy from these impregnable positions, Joffre endeavoured to outflank the German right wing, already threatened by Maunoury's advance along the Oise. Two new French armies were formed from the reserves to extend the Allied left—the Seventh, entrusted to de Castlenau, whose Second Army was transferred to Dubail, and the Tenth, the command of which was given to Maud'huy. De Castlenau's Seventh Army, though it failed to turn the enemy's flank—the movement having been anticipated by him—succeeded in extending the pressure of Maunoury's left, which had swung round by the 20th until it ran north from Compiègne to west of Lassigny, and in building the first section of Joffre's great besieging wall which, gradually extending from the Alps to the sea, became the impenetrable barrier between the enemy and his main objectives. The Allies' line was continued by de Castlenau through Roye to Albert, and thence, by Maud'huy's Tenth Army, through Arras to Lens.
Von Moltke had now been superseded in the German Higher Command by Falkenhayn, who promptly countered Joffre's new strategy by similar extensions of the German front, thus beginning the outflanking race destined only to end in stalemate on the coast. While extending their right the Germans made a strenuous effort to regain the initiative by a blow with the army group nominally commanded by the German Crown Prince on Sarrail's flank on the Meuse. It was a blow aimed at Verdun and the whole of the Allied line, which it hoped to break through at this point and so take in the rear. Verdun, however, had been rendered impenetrable by miles of powerfully protected outer defences, and practically the only success which fell to the Crown Prince on this occasion was the capture of the Camp-des-Romains and St. Mihiel on the Meuse, thus creating the remarkable salient east of Verdun which was destined to remain until the Franco-American force flattened it out in the victorious advance of the Allies four years later. The German Crown Prince fared even worse a week later, when he attacked along the main road through the Argonne towards Verdun, only to be flung back. It was after this double failure that the Germans bombarded Rheims and shattered her noble cathedral.
The crucial phase of the struggle in the West had shifted towards the coast as the first battle of the Aisne died down on 28th Sept., and the campaigns began in Artois which led in due course to the fierce struggles for the Labyrinth, the Vimy Ridge, Lens, and Loos. The extension of the French left placed the British army in an anomalous position. Even before Joffre had begun to build his barrier in this direction the British Commander-in-Chief had felt strongly that his proper sphere of action was on the Belgian frontier on the left flank of the French armies, for the two-fold purpose of defending the Channel ports and being in position to concert combined action with the British navy. He suggested this move to the north to Joffre on 29th Sept., pointing out its strategical advantages and the possibility of doing so now that the position of his force on the right bank of the Aisne had been thoroughly well entrenched. Joffre agreed in principle to General French's proposal, but postponed the movement until 3rd Oct.
Retreat from Antwerp
By this time the critical situation of the Belgian army at Antwerp had become hopeless, and the danger of a German descent on the Channel ports suddenly became acute. Since their retreat towards Antwerp after their evacuation of Brussels on 20th Aug., the Belgians had kept the Germans at bay by vigorous counter-attacks, and threatened their communications by sundry sorties from the fortress. These sorties and counter-attacks, calling for reinforcements at a time when every soldier was needed on the main fighting fronts, infuriated the Germans and led to the reign of terror which included the deliberate destruction of Louvain and similar outrages at Malines, Termonde, and elsewhere.
Having made his position secure on the Aisne, and brought up his heavy guns, the enemy began his bombardment of the outer forts of Antwerp on 28th Sept. By the 3rd of Oct. the Belgians were endangered not only by the besieging army, but also by the ever-lengthening German line which, having now been extended from Lassigny to Lille—only 38 miles from the sea—threatened to isolate the Belgian forces from the Franco-British armies. They accordingly decided that plans must be made at once to withdraw from Antwerp in the direction of Ghent, both to protect the coast-line and gain touch with the Allies. The British troops hurriedly sent to reinforce the Belgians—a brigade of Royal Marines and part of the recently formed Naval Division—had no influence on the fate of the fortress, but helped in protecting the flight of the citizens and in the final retreat of the Belgian army. Some 1500 of the Royal Naval Division were forced across the Dutch frontier and interned, and about 800 were made prisoners. The remnants of the British force, and the bulk of the Belgian army, escaped westward, leaving the Germans on 9th Oct. in possession of the deserted city. A little more and the German commander (von Beseler) might have closed the gap beyond the Scheldt through which this retreat had been made. Luckily for the Allies, too, the German Higher Command failed, as Lord French long afterwards expressed it, to gather the richer harvest which had been put within its grasp by the capture of Antwerp. There was then apparently no insuperable obstacle to an immediate German advance on Dunkirk, Calais, and Boulogne, before the Allied troops could arrive from the main theatres to prevent it. "As on the Marne, so at Antwerp, they were not prepared to seize the psychological moment and to play boldly for the great stake".
General French, who had been given no voice in the Antwerp dispositions, was now in the midst of the British move from the Aisne front to the north, where he was to be reinforced by the 7th Infantry and 3rd Cavalry Divisions, which had been landed on the Belgian coast to defend Zeebrugge and Ostend under Rawlinson's command, and the Indian contingent, which had just arrived at Orleans under Willcocks.
First Battle of Ypres
The two corps under de Castlenau and de Maud'huy were now under the supreme command of General Foch, who had orders to control all the French armies operating in the northern theatre, and was confident that it was still possible to outflank the Germans and bend them back behind the Scheldt. At the end of a fortnight the British army had been successfully transported to the north from the Aisne—after successfully holding the line of that river for twenty-five days against many desperate efforts of the enemy to break through—and had taken up its position on the left of Maud'huy's corps, the Allies' line being extended thence into Flanders by the French 8th Corps (under d'Urbal), which had been called up by Joffre to this end, as well as to help the sorely tried Belgians. Meantime the Germans, besides pressing Maud'huy hard in front of Arras, and forcing his Territorials out of Lille, had driven the retreating Belgian army out of Houthulst Forest to the line of the Yser north of Ypres, whence it took refuge behind the Yser and completed the Allied line to the coast. Rawlinson's 4th Corps, covering the retreat of the Belgian army, had hard fighting most of the way before it succeeded in joining the main