For the actions now to be followed, the opposed forces, from north to south, were as follows:
Uncertainty as to some German units, and the continual transfer on both sides, make an accurate comparison of strength impossible. M. Hanotaux[73] estimates the French forces at their maximum at 532,000, and the German at 530,000 men. This was during the battle of the Gap of Charmes, and at the end of August. On September 4, Castlenau had lost 70,000 men or more, and the 1st Army was similarly reduced in the following days. On the other hand, Heeringen took the 15th Corps with him to the Aisne on September 7. It is probable that, during the crucial struggle before the Grand Couronné, Castlenau was considerably outnumbered; and the French were markedly inferior in artillery, even when the heavy fortress guns had been brought into the field.
So long as they stood on the defensive, however, the French had the great advantage of a range of positions naturally formidable, and improved by some passable field-works. General de Curières de Castlenau, a particular star of the old aristocratic-military school, was unorthodox in one vital matter. In a study written in the spring of 1914,[74] he had concluded that the French concentration would be completed as soon as, or a little sooner than, the German. Nevertheless, he had declared for the strategical defensive; and, foreseeing a decisive battle on the Grand Couronné, the heights bordering the Gap of Charmes, and the west bank of the Mortagne, he had planned, for when the German attack should be worn down, the reaction north and south of the Forest of Vitremont which he was actually to conduct some months later. In this, Castlenau was one of the far-sighted few. The defensive idea favoured in the period when the military inferiority of France was most acutely felt had sunk into disrepute. “The system of offensive strategy, of ‘striking out,’ gained adepts, especially among the young officers,” says M. Hanotaux. “Certainly the system of a waiting strategy had not lost all its partisans: General de Castlenau represented a strong and reasoned doctrine when he advocated, for the east in particular, the offensive-defensive, and the preparation of a stand on the Meurthe at the outset, then on the Mortagne.” He was overborne in favour of the daring and gifted lieutenant and teacher who, in 1900, had insisted that “movement is the law of strategy,” that the shock must be sought, not waited for, and that, “in a war with Germany, we must go to Berlin by way of Mayence.”[75] Instead of leading to Mayence and Berlin, the French march upon Morhange and Sarrebourg had led back to the Gap of Charmes and the Grand Couronné. Tragically justified, Castlenau now had his chance. For the first time, the invaders found themselves faced by entrenchments, wire-fields, gun-pits, and observatories prepared as well as the time available had allowed.
Such a line, extending 60 miles from near Pont-à-Mousson to the north-western spurs of the Vosges, might well have followed straightly the high western banks of the Moselle, Meurthe, and Mortagne, having the fortresses of Toul and Epinal close behind. The abandonment of the beautiful city of Nancy—a garrison town, but in no sense a fortress—had usually been contemplated in the event of war: that is, perhaps, why the Kaiser so ostentatiously prepared for his ceremonial entry. Castelnau was resolved against this sacrifice. No positions, he thought, could be better defended than the crescent of hills called the Grand Couronné, of which the two horns point north-east from Nancy and the Meurthe, as though in anticipation, the northern horn ending in the twin mounts of Amance (410 and 370 metres), and the southern in a ridge extending from the Rambétant (330 m.) to the Bois de Crevic (251 m.); while the space between the tips is covered by the forest-plateau of Champenoux. On the north, the Nancy crescent is supported by the Moselle Heights, from La Rochette (406 m.), above Bouxières, to Sainte Geneviève (382 m.); and the river is closed in by sharp and thickly-wooded slopes on both banks. On the south, beyond the River Sanon, the crescent is extended by the hills of Flainval and Anthelupt, and, within a wide loop of the Meurthe, by the great bulk of Vitrimont Forest, reaching near to the large town of Lunéville. Farther south, Dubail’s divisions stretched along the high western bank of the Mortagne, and then, at an obtuse angle from Rambervillers, into the passes of the Vosges giving upon Raon-l’Etape and St. Dié.
We will follow the attack as it came up from this southern region, beginning with what must be regarded as a heavy demonstration preparatory and secondary to the chief affair, that of the Grand Couronné. After the failure to penetrate the Gap of Charmes, Heeringen had been charged to break through, or to make a feint of breaking through, the French 1st Army toward Epinal. Reinforced by the 41st and 44th Divisions and four divisions of reserves, Dubail was well resisting this pressure when, on September 4, he was required to give up his 21st Corps. At the same time, Heeringen’s XIV Corps and other troops, from the valley of the Upper Meurthe, made a desperate effort to force the two mountain ways by which alone large bodies of men could reach the Moselle valley from the northern Vosges, namely, the road from Raon-l’Etape across the Col de la Chipote to Rambervillers, and thence to Charmes or Epinal by easy routes; and the road from St. Dié, through the mountain Forest of the Mortagne, to Bruyères, and thence to Epinal. Sharp fighting, in which the French lost heavily, especially in officers, took place on September 4 and 5 at the Chipote—a bare red hump barring the pass, surrounded by fir-clad cliffs—on the twin hills by Nompatelize, and on the lesser passes south of St. Dié. The real intention of the German Command was probably no more than to pin down Dubail’s forces; it could hardly hope to pierce such a depth of mountain fastnesses in time to affect the general issue.
On the left of the 1st Army, on September 5, the German XXI Corps drove Castelnau’s 16th and Dubail’s 8th Corps out of Gerbéviller and Moyen, and passed on to the west bank of the Mortagne; but the French recovered most of this ground the same evening. On the right, the 14th Corps had to abandon the Passé du Renard and several neighbouring hills south of Nompatelize; and the 41st Division was driven up the St. Dié valley to the crest above Mandray, and beyond. On the following day, these positions also were won back in a reaction that began to threaten the German line of communications in the St. Dié valley. From this moment, the combats of the Upper Meurthe slackened and gradually expired. The battle had been definitely deplaced to the north. Heeringen, with one of his active corps, was ordered to the Chemin des Dames, where he was to stop the threatening progress of the British Army—a most significant move; two remaining corps were about to be transferred to the Bavarian Command for the struggle before Nancy, the last and greatest effort on the east. On the night of September 7, the 8th Corps repassed the poisoned waters of the Mortagne at Magnières and St. Pierremont; and everything pointed to a sweeping advance, when Dubail was summoned by the General Staff to surrender another of his best units, the 13th Corps, to re-form his whole line, and to stand still with what remained. The danger-point now lay elsewhere.
Castelnau had hardly filled the spaces left by the removal of his 15th and 9th Corps when, in the early afternoon of September 4, a cannonade of a violence hitherto unknown broke over the positions of the 2nd Army before Mont Amance, across the eastern side of Champenoux Forest, by Réméréville, Courbessaux, Drouville, and Maixe, to the east edge of the Forest of Vitrimont. The first attack came upon the right of this front, waves of Bavarian infantry flooding upon the barricaded farms and hamlets and the trenched hillsides. Behind Serres and in advance of Maixe, the 39th Division was pressed back; but, as a whole, the front of the 20th Corps was little changed; and, on its right, the 16th Corps was not yet disturbed. While this hell-fire was being lit, Kluck was racing southward across the Marne and a regiment of Cuirassiers, in full array, was marching through the streets of Metz, under the eyes of the Emperor, who, after visiting the Verdun front, was waiting for the hour of his triumphal entry into Nancy.
At nightfall the conflict waxed more furious. The German plan, as it was presently revealed, was to burst through the opening of the Grand Couronné, and, while maintaining a strong pressure upon the southern horn of the crescent, to envelop the northern horn by a rapid push from Pont-à-Mousson up the Moselle valley, this move by fresh troops from Metz furnishing the precious element of surprise.[76]
Throughout the night of the 4th, the storm raged about the rampart of Nancy. Doubtless the German Command had chosen the way between the Champenoux Forest and the Rambétant as the least difficult for the first phase of its last effort; and, although night attacks are manifestly dangerous, the calculation in this case that the defenders would suffer most from confusion appears to have been justified. Boldly adventuring by dark forest paths and misty vales, the Bavarian Corps of Martini ejected the fore-posts of the 20th Corps from the hills near Lunéville, from Einville Wood, and the ridges between Serres and Drouville. Maixe and Réméréville were lost, retaken, and lost again. Erbéviller, Courbessaux, lesser hamlets, and farmsteads flamed across the countryside, a fantastic spectacle that deepened the terror of the remaining inhabitants, who had taken refuge in their cellars or the fields. General Fayolle’s reservists of the 70th Division stood bravely on the east edge of Saint Paul Forest and at Courbessaux. On their left the 68th lost Champenoux village at dawn, but recaptured it a few hours later; while, behind it, the 64th busied itself in completing another line of resistance from the important point of the Amezule gorge (on the highroad from Nancy to Château-Salins, midway between Laneuvelotte and Champenoux), by Velaine and Cerceuil, to the Rambétant.