by Hew Strachan
Joffre’s order did not specify the task of the 1st, 2nd, 3rd, and 4th armies. That was clear enough. They must hold, or there would be no overall success. For, while the drama of the Marne lies to the west, the German hopes of winning the battle now lay to the east. The 5th German army was struggling to break through between Verdun and Toul, and to envelop the French defences south of Nancy from the north. The 6th and 7th armies, whose dilatoriness was irking Moltke by the end of August, were reinforced with nearly seventy heavy batteries, many of them drawn from the fortifications at Metz. On 4 September they renewed their attack along the Moselle.
Moltke’s directive of 2 September, bringing the right wing away from Paris, had aroused criticism within German general headquarters. Most recognized that the French had withdrawn troops from the Toul-Épinal front—the Germans now had a superiority of seven divisions there—but could not identify whither they had gone. Falkenhayn thought they were west of Verdun, opposite the 4th and 5th German armies. He advocated a wholly new operation, effectively splitting the German advance in two. The 1st, 2nd, 3rd, and 4th armies should aim for Paris. The 5th should incline towards its left in the direction of the Vosges, and should co-operate with the attack of the 6th and 7th.134 Some of this thinking is evident in Moltke’s directive, dispatched at 6.30 p.m. on 4 September. By now aware of Kluck’s disobedience and of the consequent danger to the right flank from Paris, Moltke detailed not only the 1st army (between the Marne and the Oise) but also the 2nd (between the Marne and the Seine) to act as flank guards. The 3rd was to continue facing south, but in sustaining its link with the 2nd army was in danger of overstretching itself. The 4th and 5th were to attack to the south-east, and the 6th and 7th to the south-west. Moltke’s directive embraced, although to a lesser degree, the divergent objectives set by Falkenhayn, and its targets were distant rather than immediate. But, if it had a focus it was on the German left flank, on the Argonne, on the Meuse, and at Nancy. These were the very areas whose fortifications the original plan had been designed to avoid.
Kluck did not receive Moltke’s order until 7.00 a.m. the following morning. By then the 1st army had begun its day’s march. Moreover, the order’s contents made little sense to an army commander unaware of the overall situation. Kluck had won a succession of victories, engaged in a rapid advance without check, and yet was being asked to fall back. Furthermore, his doctrine was envelopment: a directive whose philosophy was breakthrough was inherently unsympathetic. Not until the afternoon, when Hentsch, OHL’s head of intelligence, visited 1st army headquarters, did Kluck grasp what was intended. But even then neither he nor Hentsch imagined a general French offensive to be imminent. Hentsch’s concern was to secure the Germans’ line of communications on their open flank. Kluck still assumed that the French and the BEF were defeated. The main reconnaissance effort of II corps was to the front, and its aeroplanes reported the roads between the Marne and the Seine clogged with troops marching south; Kluck’s flank guard, IV reserve corps, had no integral airpower and was therefore ignorant of the situation to the west. Kluck could see no need for urgency in the execution of the order.
Contact on the Ourcq between Kluck’s flanking force, IV reserve corps, and some French units was made at dusk on 4 September. During the course of the 5th Maunoury’s pressure on the Ourcq built up, and by midnight Kluck was aware that IV reserve corps was heavily outnumbered. Joffre’s order of the day, marking the beginning of the French attack, was known to OHL and distributed to the individual armies, before it was read by front-line French soldiers. Kluck was, therefore, able to see the significance of the Ourcq battle to the overall French design, and concluded that a rapid victory by the 1st German army over the French 6th would unhinge the French plan. On 7 September he belatedly executed his orders to protect the German flank. The weight of 1st army, two corps, which had been on Bülow’s right flank, were marched 100 kilometres on to the northern flank of IV reserve corps in an effort to outflank Maunoury. Maunoury’s position was desperate. Reinforcements, including some (but fewer than legend suggests) borne in commandeered taxis, were pushed into the battle from Paris. The effect of Kluck’s move was to open a gap between the 1st and 2nd German armies.
Kluck was not unduly perturbed about the position to his front. It was screened by two cavalry corps, von der Marwitz’s and Richthofen’s from 2nd army. Von der Marwitz’s corps had just had two days’ rest to reshoe their horses and refurbish their weapons in anticipation of heavy fighting on the Seine. It seemed sufficient to contain any threat the BEF might present. The latter had continued its retreat on 5 September, and did not begin its advance until the morning of the 6th. Its line of march, therefore, was not to the east as intended, but to the north-east and then north, as it entered the gap created by Kluck’s turn towards Paris. This had two effects. First, any ongoing concerns on the part of Sir John French about his flanks were rendered redundant by the fact that the BEF began 16 kilometres south of its designated start line, and so behind—not ahead of—the adjacent French armies. Secondly, Joffre’s line was echeloned back from the left, so that if need be its components could turn in to the right to provide mutual support.
The German efforts to win the battle in the east began quickly to disintegrate. From 31 August Moltke had considered weakening the left wing, not in order to reinforce the right (something which did not seem particularly necessary until 6 September itself), but to guard his lines of communication, especially in Belgium. Reports of British landings in Ostend and of the dispatch of a Russian corps, transported by the Royal Navy, preyed on Moltke’s fears. Since the task of 6th and 7th armies was now to hold the French, while the 4th and 5th broke through, the left wing could be seen as having disposable forces. Moltke began to prepare to shift the 7th army to Belgium, and so weakened the Moselle attack. Castelnau, having threatened withdrawal on the 6th, was still solid in his position on the 8th.
Joffre became more worried about the situation around Verdun and to its west. Sarrail, who had taken over command of the French 3rd army, made great play of maintaining the city and its fortifications within the French line. This worked to the extent that the German 5th army increasingly committed itself to its assault, so weakening its efforts on its flanks. But it worried Joffre, who saw the defence of the town as secondary to the need to ensure the integrity of the line itself. A German attack south of Verdun did get across the Meuse, but was checked by the French forts along the river. The 3rd army’s concentration on Verdun opened a gap between it and Langle de Cary’s 4th. However, the German 4th army did not exploit it. Foch’s 9th army was caught in a dangerous position. Its right flank was exposed by the 4th’s need to maintain contact with Sarrail. Therefore, while Foch’s left faced the obstacle of the marshes of St Gond and was supported by the 5th’s advance, his right extended over undulating ground and then ended at Mailly with a 20-kilometre gap covered by a single cavalry division. XXI corps, ordered to close the gap, did not come up until the evening of the 8th. Fortunately for the French, the hole in their line was matched by one in the Germans’, Hausen’s 3rd army being stretched too wide. But it was with Hausen and opposite Foch’s right that German hopes of victory now resided. In the grey light of the morning of 8 September, to avoid the devastating effects of the French 75 mms, Hausen’s army attacked without artillery preparation and with the bayonet, routing Foch’s XI corps. Foch, denied assistance by Langle de Cary, appealed to Franchet d’Esperey. The 5th army generously released its right-hand corps, allowing Foch to move a division behind his line from left to right and so stabilize the position. Foch’s army had been beaten, but Foch himself had doggedly refused to admit it. Although the ground provided little shelter, it optimized the ricochet fire of the 75 mm. Some of Foch’s guns fired a thousand rounds each per day. His repeated calls to counter-attack had elicited scepticism from his troops but not disobedience. The line held.135
By 7 September Bülow was worried about the position of the 2nd army. Its front engaged by the French
5th army, its left by Foch’s left, its right and rear were completely exposed to the advance of the BEF. The focus of Kluck’s battle—his desire for envelopment and his protection of his right wing—was not Bülow’s. Kluck had not told Bülow of his intentions, nor of the withdrawal of the two corps from Bulow’s flank. On 8 September Bülow pulled back his exposed right wing, so that 2nd army was deployed on a north-south line and more to the east. The gap between 1st and 2nd armies was thus increased. Neither Kluck nor Bülow thought to keep either each other or OHL informed of what was happening. Deprived of information, Moltke ceased to issue directives. Co-ordination of the German armies had collapsed.
However, on the morning of the 8th Moltke learned of the BEF’s advance through wireless intercepts. Still without effective communications—wireless links between OHL and the army commanders were ordered on 6 September but were not established until 2.30 p.m. on the 9th—Moltke decided to send Hentsch on a mission to establish the situation along the entire front. Moltke was not convinced that any retreat on the part of the right wing was necessary, but Hentsch was authorized to allow it if that was the only way to close the gap between the 1st and 2nd armies. Hentsch first visited the 5th, 4th, and 3rd armies, and found all in satisfactory positions. Not until 7.45 p.m. did he reach Bülow. Bülow had already decided that a retreat, on converging lines to close the gap, was necessary. Hentsch did not oppose Bülow, not least because he did not know Kluck’s position. But if Bülow did fall back, Kluck would have no option but to conform.
Hentsch’s drive the following morning to Kluck’s headquarters, although only 90 kilometres distant, took five hours on the crowded roads. Kluck was not there when Hentsch arrived. Instead, he saw the chief of staff, von Kuhl. Kluck’s absence has allowed his defenders to argue that the 1st army was on the verge of defeating Maunoury’s 6th, and that it could then have turned against the BEF and won the battle of the Marne. Given the exhausted state of the 1st army and the fact that it was outnumbered, this case is hard to sustain. The BEF’s advance had begun to threaten the 1st army as well as the 2nd, causing Kluck to pull back his left wing on the Ourcq on 8 September, and so releasing some of the German pressure on Maunoury. It is just as possible to contend, therefore, that Kluck had already acknowledged the need to retreat before Hentsch arrived at his headquarters. Hentsch’s own demeanour may have been somewhat flustered: it was he who was feeding Moltke’s worries about the Belgian lines of communication, and any inherent pessimism would have found confirmation from Bülow. He told von Kuhl that the 2nd army was defeated and being driven back.136 He therefore ordered the 1st army to retreat. The 1st army’s line of march had to be due north, not north-east towards the 2nd army, in order to avoid passing across the front of the BEF. Hentsch’s hope that the 1st and 2nd armies would converge on the Vesle was thus disappointed. Kluck was once again subordinated to Bülow on 10 September, in order to aid the conjunction of the two armies. But it required the insertion of fresh troops definitively to close the gap.
Moltke’s hopes of limiting the extent of the retreat had not entirely dissipated. On his return to OHL Hentsch was relatively buoyant, and saw the withdrawal as confined to the 1st and 2nd armies. The prospect of the 4th and 5th armies capturing Verdun would help cover the movement on the right. On 11 September Moltke himself left Luxembourg to visit the armies’ headquarters. The key to restricting the retreat was the state of the hard-pressed 3rd army—in the centre and thus pulled back on its right and forward on its left. But Hausen was sick and his army exhausted. Moltke spoke to Bülow on the telephone while he was at Hausen’s headquarters: the French advance, Bülow reported, pushing in a north-easterly direction, was about to strike the centre of the 3rd army, so as to threaten the communications of the 4th and 5th. Moltke decided to order a general retreat along the whole front. The German armies would both contract and fall back to the Aisne. In Lorraine, Moltke’s worries about Belgium—reinforced by a sortie from Antwerp begun on 9 September and sustained until the 12th—led to the withdrawal of ten divisions, and a separate retreat in front of Nancy and to the south.
During the German advance Moltke had resisted the premature celebration of victory: where, he wondered, were the prisoners and the guns of a defeated army? As the allies advanced they asked themselves the same question. Its chief of staff described the 1st German army as completely disorganized and its individual corps no longer in being. But, if that was the case, it is proof of the German army’s powers of regeneration. Order was restored, by divisions, by 12 September. Within the 1st army, Bloem’s company of Brandenburg grenadiers had no sense of defeat and had time to drink ninety bottles of claret on its march.137 Indeed, empty bottles were the most obvious and frequent signs of the Germans’ recent departure. The pioneers, who in the German army were treated very much as combat troops, and at least one company of whom was attached to each division and one battalion to each corps, were sent ahead to prepare defensive positions on the Aisne. The line the Germans had chosen followed the steep ridge on the north bank of the river. It covered all the main river crossings, and spurs projected into the valley to break up attacks. The position was flanked on its north-west by the forests around Compiègne, and to the south-east it ran along the hills of Reims and then into the woods of the Argonne. To its north was a possible second line of defence on the Aillette. By 13 September Kluck’s and Bülow’s armies were both safely across the Aisne. VII reserve corps, released by the fall of Maubeuge, was thrown into the gap between the two armies, and on the 14th was joined by Heeringen’s 7th army headquarters and XV corps, both originally withdrawn from Alsace to go to Belgium. By the evening of the 13th the major crisis for the Germans was already passing.
The advance of the BEF into the gap was particularly slow. Only on the left, where the Germans destroyed the bridges and defended the crossings against the newly formed III corps, was there serious resistance. I corps on the right was checked by a single cavalry division and II corps by a brigade and von der Marwitz’s corps. The latter’s horses were now beginning to succumb to lack of fodder.138 The Germans had not even secured the Marne crossings. Total British casualties in the Marne battle were 1,701. And yet between 6 and 9 September the average progress of the BEF’s own cavalry was only 14.5 kilometres a day.139
Joffre’s orders on 11 September directed the 3rd, 4th, and 9th French armies against the Germans’ eastern group, and the left of the 5th, the BEF, and the 6th against the western. His hope was to exploit the gap in order to effect a breakthrough, and so separate and destroy Kluck’s and Bülow’s armies. By 12 September both Franchet d’Esperey and Sir John French had recognized the need for energetic and rapid pursuit, seeking objectives beyond the Chemin des Dames, the road running along the northern ridge of the Aisne valley. But their subordinate commanders were more cautious. Fears of an encounter battle were not dispelled. The weather on the 12th was wet, hampering the advance and, as importantly, aerial reconnaissance. The allies knew that the Germans were adapting their order of battle, but found it hard rapidly to impose order on the information available. On 14 September GQG’s 2èmebureau received 487 dispatches: it appreciated that the Germans had withdrawn XV corps from Alsace, but then placed it simultaneously on the Russian front, at Metz, and in Belgium.140 By the 13th the 5th French army was athwart Reims and the British were across the Aisne on the Chemin des Dames. XVIII corps, on the 5th’s left, was well forward at Craonne. The Aisne bridges near Berry-au-Bac, between Craonne and Reims, were clear. At midday one French cavalry division was operating at Sissone, 20 kilometres beyond the Aisne, deep into the breach between Kluck and Bülow. But as the 7th German army began to form these forward units fell back, and the Berry-au-Bac position was abandoned without a fight. The British renewed their attack on 14 September but found the going tough and their positions overlooked by the Germans. By the evening even Franchet d’Esperey had recognized the strength of the German position. Joffre’s directive that night, reflecting the tactical difference betwe
en all-out pursuit and a methodical attack against a prepared position, announced the switch from the first to the second: ‘that means that every position, as soon as it is occupied, must be fortified.’141 On the 15th the 5th army was fighting a defensive battle between Craonne and Reims. It was to continue to do so well into October.
Critics of the allied failure to exploit the victory on the Marne argue that two strategic options presented themselves. The first, which is what the allies attempted, was to drive into the gap between Kluck and Bülow. But they moved too slowly and too cautiously. That they did so, given the experience of the earlier German victories, and given the break in the weather after 10 September, is not surprising. Indeed, the fact that the allied armies were able to turn, to fight, and then to push forward at all was itself a major achievement. Both the French and British armies (like the Germans) had marched off the maps with which they had been issued. Even more importantly, the soldiers themselves were exhausted. On the thirteen days of the retreat the BEF’s cavalry had had an average of three hours’ rest in every twenty-four and the infantry four hours.142 One division in the French 5th army calculated that in the eight days preceding the battle it had marched 22 kilometres a day.143 The thrust of Joffre’s orders from 7 September, to close the line up, and to direct the line of march to the north-east, was a reflection both of his justified hope that the German centre would break (as Bülow feared it would on the 11th) and of the physical resources of the men under his command.
The second option at least theoretically available to Joffre was to exploit the Germans’ open flank to the north. The territory bounded in the west by the line Paris to Antwerp, through which the German communications ran, was effectively untenanted. Two forces seemed to be available to take this opportunity. The first was the 6th army. Joffre had been urging Maunoury to gain ground on the right bank of the Ourcq ever since 7 September, and his orders of the 11th directed it even further north, to the right bank of the Oise. But Maunoury’s army was short of cavalry and had no bridging equipment. Furthermore, it was committed to the BEF’s left flank: when Kluck turned his main weight against the 6th army Joffre could not simultaneously exploit the gap in the German front and seek to envelop the German right. The evenly balanced situation around Verdun and Nancy meant that he could not easily or rapidly effect a further major concentration in the west. On 12 September he reinforced the 6th army with two more divisions, hoping that Maunoury would outflank the German line and keep Kluck so engaged that he would be unable to close the gap with Bülow. But the 6th army’s passage of the Aisne was no faster than that of the others, and by the 13th Maunoury found himself facing Kluck frontally and in strong positions.