A tactical offensive into the Ardennes, a glorified reconnaissance and raid, strictly limited and controlled, might perhaps be justified. The advance ordered on the evening of the defeat of Morhange, and executed on the two following days, engaging the only general reserve at the outset in a thickly-wooded and most difficult country, was too large for a diversion, and not large enough for the end declared: it failed completely and immediately—in a single day, August 22—with heavy losses, especially in officers.18 Here, again, there was an approximate equality of numbers; again, the French were lured on to unfavourable ground, and, before strong entrenchments, crushed with a superiority of fire. Separated and surprised—the left south-west of Palliseul, the centre in the forests of Herbeumont and Luchy, the Colonial Corps before Neufchateau and Rossignol, where it fought literally to the death against two German corps strongly entrenched, the 2nd Corps near Virton—the body of the 4th Army was saved only by a prompt retreat; and the 3rd Army had to follow this movement. True, the German IV Army also was much exhausted; and an important part of the enemy’s plan missed fire. It had been soon discovered that the Meuse from Givet to Namur was but lightly held; and the dispatch thither of the Saxon Army, to cut in between the French 4th and 5th Armies, was a shrewd stroke. Hausen was late in reaching the critical point, about Dinant, and, by slowness and timidity, missed the chance of doing serious mischief.
Meanwhile, between the fields of the two French adventures into German Lorraine and Belgian Luxembourg, the enemy had been allowed without serious resistance to occupy the Briey region, and so to carry over from France to Germany an iron- and coal-field of the utmost value. “Briey has saved our life,” the ironmasters of the Rhineland declared later on, with some exaggeration. Had it been modernised, the small fortress of Longwy, situated above the River Chiers three miles from the Luxembourg frontier, might have been an important element in a defence of this region. In fact, its works were out of date, and were held at the mobilisation by only two battalions of infantry and a battery and a half of light guns. The Germans summoned Colonel Darche and his handful of men to surrender on August 10; but the place was not invested till the 20th, the day on which the 3rd Army was ordered to advance toward Virton and Arlon, and to disengage Longwy. Next day, Ruffey was north and east of the place, apparently without suspecting that he had the Crown Prince’s force besieging it at his mercy. On the 22nd, it was too late; the 3rd and 4th Armies were in retreat; Longwy was left to its fate.19
The completest surprise naturally fell on the west wing of the Allies; and, had not the small British force been of the hardiest stuff, an irreparable disaster might have occurred. Here, with the heaviest preponderance of the enemy, there had been least preparation for any hostilities before the crisis was reached. On or about August 10, we war correspondents received an official map of the “Present Zone of the Armies,” which was shown to end, on the north, at Orchies—16 miles S.E. of Lille, and 56 miles inland from Dunkirk. The western half of the northern frontier was practically uncovered. Lille had ceased to be a fortress in 1913, though continuing to be a garrison town; from Maubeuge to the sea, there was no artificial obstacle, and no considerable body of troops.20 The position to be taken by the British Expeditionary Force—on the French left near Maubeuge—was only decided, at a Franco-British Conference in London, on August 10.21 On August 12, the British Press Bureau announced it as “evident” that “the mass of German troops lie between Liège and Luxembourg.” Three days later, a Saxon advance guard tried, without success, to force the Meuse at Dinant. Thus warned, the French command began to make the new disposition of its forces which has been alluded to.
Lanrezac had always anticipated the northern attack, and had made representations on the subject without effect.22 At last, on August 16, General Joffre, from his headquarters at Vitry-le-François, in southern Champagne, agreed to his request that he should move the 5th Army north-westward into the angle of the Sambre and Meuse. At the same time, however, its composition was radically upset, the 11th Corps and two reserve divisions being sent to the 4th Army, while the 18th Corps and the Algerian divisions were received in compensation. On August 16, the British Commander-in-Chief, after seeing President Poincaré and the Ministers in Paris, visited the Generalissimo at Vitry; and it was arranged that the Expeditionary Force, which was then gathering south of Maubeuge, should move north to the Sambre, and thence to the region of Mons. On the same day, General d’Amade was instructed to proceed from Lyons to Arras, there to gather together three Territorial divisions of the north which, reinforced by another on the 21st and by two reserve divisions on the 25th, ultimately became part of the Army of the Somme. Had there been, on the French side, any proper appreciation of the value of field-works, it might, perhaps, not have been too late to defend the line of the Sambre and Meuse. It was four or five days too late to attempt a Franco-British offensive beyond the Sambre.
To do justice to the Allied commanders, it must be kept clearly in mind that they had (albeit largely by their own fault) but the vaguest notion of what was impending. Would the mass of the enemy come by the east or the west of the Meuse, by the Ardennes or by Flanders, and in what strength? Still sceptical as to a wide enveloping movement, Joffre was reluctant to adventure too far north with his unready left wing; but it seemed to him that, in either case, the intended offensive of the French central armies (the 3rd and 4th) across the Ardennes and Luxembourg frontier might be supported by an attack by Lanrezac and the British upon the flank of the German western armies—the right flank, if they passed by the Ardennes only; the left, if they attempted to cross the Flanders plain toward the Channel. Thus, it was provisionally arranged with the British Commander that, when the concentration of the Expeditionary Force was complete, which would not be before the evening of August 21, it should advance north of the Sambre in the general direction of Nivelles (20 miles north-east of Mons, and half-way between Charleroi and Brussels). If the common movement were directed due north, the British would advance on the left of the 5th Army; if to the north-east or east, they would be in echelon on its left-rear. General Joffre recognised that the plan was only provisional, it being impossible to define the projected manœuvre more precisely till all was ready on August 21, or till the enemy revealed his intentions.
It was only on the 20th that two corps of the French 5th Army reached the south bank of the Sambre—one day before Bülow came up on the north, with his VII Corps on his right (west), the X Reserve and X Active Corps as centre, the Guard Active Corps on his left, and the VII Reserve (before Namur) and Guard Reserve Corps in support. In this posture, on the evening of August 20, Lanrezac received General Joffre’s order to strike across the Sambre. Namur was then garrisoned by the Belgian 4th Division, to which was added, on the 22nd, part of the French 8th Brigade under General Mangin. Lanrezac had not even been able to get all his strength aligned on the Sambre when the shock came.23 On the 21st, his five corps were grouped as follows: The 1st Corps (Franchet d’Espérey) was facing east toward the Meuse north of Dinant, pending the arrival, on the evening of the 22nd, of the Bouttegourd Reserve Division; the 10th Corps (Defforges), with the 37th (African) Division, on