VII. The centurions sent to reconnoitre had selected for the establishment of the camp the heights of Neuf-Mesnil. These descend in a uniform slope to the very banks of the river. Those of Boussières, to which they join, end, on the contrary, at the Sambre, in sufficiently bold escarpments, the elevation of which varies from five to fifteen mètres, and which, inaccessible near Boussières, may be climbed a little lower, opposite the wood of Quesnoy. The Sambre, in all this extent, was no more than about three feet deep. On the right bank, the heights of Haumont, opposite those of Neuf-Mesnil, descend on all sides in gentle and regular slopes to the level of the river. In the lower part, they were bare for a breadth of about 200 Roman paces (300 mètres), reckoning from the Sambre; and then the woods began, which covered the upper parts. It was in these woods, impenetrable to the sight, that the Belgæ remained concealed. They were there drawn up in order of battle: on the right, the Atrebates; in the centre, the Veromandui; on the left, the Nervii; these latter facing the escarpments of the Sambre. On the open part, along the river, they had placed some posts of cavalry. (See Plate 10.)

Cæsar, ignorant of the exact position where the Belgæ were encamped, directed his march towards the heights of Neuf-Mesnil. His cavalry preceded him, but the order of march was different from that which had been communicated to the Nervii by the deserters; as he approached the enemy, he had, according to his custom, united six legions, and placed the baggage in the tail of the column, under the guard of the two legions recently raised, who closed the march.

The cavalry, slingers, and archers passed the Sambre and engaged the cavalry of the enemy, who at one moment took refuge in the woods, and at another resumed the offensive, nor were ever pursued beyond the open ground. Meanwhile, the six legions debouched. Arrived on the place chosen for the camp, they began to retrench, and shared the labour among them. Some proceeded to dig the fosses, while others spread themselves over the country in search of timber and turf. They had hardly begun their work, when the Belgæ, perceiving the first portion of the baggage (which was the moment fixed for the attack), suddenly issue from the forest with all their forces, in the order of battle they had adopted, rush upon the cavalry and put it to rout, and run towards the Sambre with such incredible rapidity that they seem to be everywhere at once—at the edge of the wood, in the river, and in the midst of the Roman troops; then, with the same celerity, climbing the hill, they rush towards the camp, where the soldiers are at work at the retrenchments. The Roman army is taken off its guard.

Cæsar had to provide against everything at the same time. It was necessary to raise the purple standard as the signal for hastening to arms,[262] to sound the trumpets to recall the soldiers employed in the works, to bring in those who were at a distance, form the lines, harangue the troops, give the word of order.[263] In this critical situation, the experience of the soldiers, acquired in so many combats, and the presence of the lieutenants with each legion, helped to supply the place of the general, and to enable each to take, by his own impulse, the dispositions he thought best. The impetuosity of the enemy is such that the soldiers have time neither to put on the ensigns,[264] nor to take the covering from their bucklers, nor even to put on their helmets. Each, abandoning his labours, runs to range himself in the utmost haste under the first standard which presents itself.

The army, constrained by necessity, was drawn up on the slope of the hill, much more in obedience to the nature of the ground and the exigencies of the moment than according to military rules. The legions, separated from one another by thick hedges, which intercepted their view, could not lend each other mutual succour; they formed an irregular and interrupted line: the 9th and 10th legions were placed on the left of the camp, the 8th and 11th in the centre, the 7th and 12th on the right. In this general confusion, in which it became as difficult to carry succour to the points threatened as to obey one single command, everything was ruled by accident.

Cæsar, after taking the measures most urgent, rushes towards the troops which chance presents first to him, takes them as he finds them in his way, harangues them, and, when he comes to the 10th legion, he recalls to its memory, in a few words, its ancient valour. As the enemy was already within reach of the missiles, he orders the attack; then, proceeding towards another point to encourage his troops, he finds them already engaged.

The soldiers of the 9th and 10th legions throw the pilum, and fall, sword in hand, upon the Atrebates, who, fatigued by their rapid advance, out of breath, and pierced with wounds, are soon driven back from the hill they have just climbed. These two legions, led no doubt by Labienus, drive them into the Sambre, slay a great number, cross the river at their heels, and pursue them up the slopes of the right bank. The enemy, then thinking to take advantage of the commanding position, form again, and renew the combat; but the Romans repulse them anew, and, continuing their victorious march, take possession of the Gaulish camp. In the centre, the 8th and 11th legions, attacked by the Veromandui, had driven them back upon the banks of the Sambre, to the foot of the heights, where the combat still continued.

While on the left and in the centre victory declared for the Romans, on the right wing, the 7th and 12th legions were in danger of being overwhelmed under the efforts of the whole army of the Nervii, composed of 60,000 men. These intrepid warriors, led by their chief, Boduognatus, had dashed across the Sambre in face of the escarpments of the left bank; they had boldly climbed these, and thrown themselves, in close rank, upon the two legions of the right wing. These legions were placed in a position the more critical, as the victorious movements of the left and centre, by stripping almost entirely of troops that part of the field of battle, had left them without support. The Nervii take advantage of these circumstances: some move towards the summit of the heights to seize the camp, others outflank the two legions on the right wing (aperto latere).

As chance would have it, at this same moment, the cavalry and light-armed foot, who had been repulsed at the first attack, regained pell-mell the camp; finding themselves unexpectedly in face of the enemy, they are confounded, and take to flight again in another direction. The valets of the army, who, from the Decuman gate and the summit of the hill, had seen the Romans cross the river victoriously, and had issued forth in hope of plunder, look back; perceiving the Nervii in the camp, they fly precipitately. The tumult is further increased by the cries of the baggage-drivers, who rush about in terror. Among the auxiliaries in the Roman army, there was a body of Treviran cavalry, who enjoyed among the Gauls a reputation for valour. When they saw the camp invaded, the legions pressed and almost surrounded, the valets, the cavalry, the slingers, the Numidians, separated, dispersed, and flying on all sides, they believed that all was lost, took the road for their own country, and proclaimed everywhere in their march that the Roman army was destroyed.

Cæsar had repaired from the left wing to the other points of the line. When he arrived at the right wing, he had found the 7th and 12th legions hotly engaged, the ensigns of the cohorts of the 12th legion collected on the same point, the soldiers pressed together and mutually embarrassing each other, all the centurions of the 4th cohort and the standard-bearer killed; the standard lost; in the other cohorts most of the centurions were either killed or wounded, and among the latter was the primipilus Sextius Baculus, a man of rare bravery, who was destined soon afterwards to save the legion of Galba in the Valais. The soldiers who still resisted were exhausted, and those of the last ranks were quitting the ranks to avoid the missiles; new troops of enemies continually climbed the hill, some advancing to the front against the Romans, the others turning them on the two wings. In this extreme danger, Cæsar judges that he can hope for succour only from himself: having arrived without buckler, he seizes that of a legionary of the last ranks and rushes to the first line; there, calling the centurions by their names and exciting the soldiers, he draws the 12th legion forward, and causes more interval to be made between the files of the companies in order to facilitate the handling of their swords. His example and encouraging words restore hope to the combatants and revive their courage. Each man, under the eyes of their general, shows new energy, and this heroic devotedness begins to cool the impetuosity of the enemy. Not far thence, the 7th legion was pressed by a multitude of assailants. Cæsar orders the tribunes gradually to bring the two legions back to back, so that each presented its front to the enemy in opposite directions. Fearing no longer to be taken in the rear, they resist with firmness, and fight with new ardour. While Cæsar is thus occupied, the two legions of the rear-guard, which formed the escort of the baggage (the 13th and 14th), informed of what was taking place, arrive in haste, and appear in view of the enemy at the top of the hill. On his part, T. Labienus, who, at the head of the 9th and 10th legions, had made himself master of the enemy’s camp on the heights of Haumont, discovers what is passing in the Roman camp. He judges, by the flight of the cavalry and servants, the greatness of the danger with which Cæsar is threatened, and sends the 10th legion to his succour, which, re-passing the Sambre, and climbing the slopes of Neuf-Mesnil, runs in haste to fall upon the rear of the Nervii.