Caesar: Life of a Colossus

by Adrian Goldsworthy

  The Remi were closely related to the Suessiones, following the same customs and laws, and at times ruled by the same leaders. It is hard to know whether their readiness to join the Romans was a pragmatic acknowledgement of their inability to resist the sudden appearance of Caesar, or was based on rivalry with and fear of the other tribes. Certainly, the Remi were the first target of the Belgic coalition, whose army advanced to assault Bibrax, one of the Remi's main towns (probably modern Vieux-Laon). Caesar had advanced across the Aisne, which lay on the tribe's borders, and camped on the far bank. He left a detachment under the legate Sabinus on the other side of the river to build a fort protecting the bridge. Bibrax was about 8 miles away, and its leader - one of the chieftains who had led the delegation to Caesar - now sent word that he could not hold out much longer unless he received help. Guided by the men who had brought this message, the proconsul sent his Numidian, Cretan and Balearic light troops to slip into the town under cover of darkness. The method used by the Belgians for attacking a fortification was simple - a barrage of sling stones and other missiles pinned the defenders down, while other warriors advanced holding their shields over their heads and undermined the wall. The skilled archers and slingers sent by Caesar would have made this extremely difficult, and the Belgians abandoned the attempt, contenting themselves with ravaging the surrounding area, setting fire to the small villages and farms dotted about the countryside. They then moved to confront Caesar, camping 2 miles from the Roman position, with a valley between them. Caesar claims that the fires in the Belgians' sprawling encampment covered an area of some 8 miles.15

  For days both sides then watched each other. There were cavalry skirmishes, by which Caesar gauged the quality of this new enemy and judged that his own men would be more than a match for them in most situations. His camp was on high ground with the River Aisne to the rear. On the slope in front he deployed his six legions with battle experience, leaving the two recently recruited formations to guard his camp - an echo of the deployment against the Helvetii. With no natural feature to protect the flanks, the legionaries dug a 400-pace (roughly 130 yards) ditch on each side, running back at right angles from the main line. Each ditch led up to a small fort, in which were emplaced light artillery pieces or scorpions, capable of firing heavy bolts with tremendous force and accuracy over distances far greater than any missile weapon the Belgians possessed. Sulla had once entrenched his position in much the same way to secure his flanks against an enemy army that was markedly superior in numbers. The Belgians would have to advance up the gentle slope before attacking the Roman position from the front, and the advantage of such a position had been clearly demonstrated the year before near Bibracte. To make matters worse for the Belgians, in the bottom of the valley between the two positions was a stream and an area of marsh. These were not impassable obstacles, but would have slowed an attack down and caused a line to fall into disorder. It was unlikely that the opposition would give the attacker the opportunity to stop and redress the line before continuing the advance.16

  Caesar's position was a strong one and he could be confident of beating off even the heaviest of attacks. However, the Belgic host showed no sign of charging to its doom and was content to form up on the far side of the valley, waiting for the Romans to cross the boggy ground and fight at a disadvantage. This was always the risk for a commander who took up a very strong position, for if the advantages it gave were obvious, then there was little incentive for the enemy to engage. Both sides sent forward their cavalry, and the allied horsemen gained a slight advantage over the Belgian horse before Caesar withdrew them. Realising that a full-scale battle was not going to develop, the legions were ordered back to camp to rest. Reaching the same conclusion, the Belgic commanders sent a part of the army to ford the River Aisne and either threaten the Roman supply line by capturing the fort protecting the bridge, or draw Caesar off by ravaging the lands of his newfound allies, the Remi. The outpost at the bridge reported this new threat and Caesar responded by personally leading his cavalry, Numidians, and the other light troops back across to the far side of the river. They managed to catch the Belgic warriors when only a few had got across. The latter were surrounded and dealt with by the cavalry, while the missile troops shot down the other warriors as they waded through the water. After suffering heavy losses, the Belgians withdrew

  It was a difficult task to keep any tribal army in the field for any length of time, since their logistical arrangements tended to be extremely basic. Only a certain amount of food would have been carried by the warriors, or the wives and servants who in many tribes accompanied them to battle. In the summer months it was often possible to find food and forage from the countryside, but the quantities to be seized in this way were limited, and soon exhausted if the army remained in one place for any length of time. The Belgian army in 57 BC was exceptionally large, even if we must treat the figures given with some caution, and so the problems of supply were made considerably worse. The attack on Bibrax had failed, as had the attempt to cross the river and get behind the Romans. Caesar had shown himself willing to fight only if the Belgians put themselves at a severe disadvantage. He had doubtless told his men that the reluctance of the enemy to attack the Roman position showed that they were frightened. Galba and the Belgian chieftains could equally have assured their warriors that the Roman refusal to come down from their hilltop and trenches was proof that they feared the might of the tribes. The campaign had not been especially successful for them so far, but they had shown their numbers and confidence to this new enemy, and Caesar had not risked attacking their main force. It is possible that Galba and the other leaders felt that they had demonstrated their strength and that this might be enough to deter further invasion. There often seems to have been strong elements of display and gesture in inter-tribal warfare, so we do not necessarily need to follow Caesar and see the Belgians' next action in purely pragmatic terms. Yet the practical factors were undeniable, for the army had almost run out of food and could not stay where it was for much longer. In addition, news had arrived that the Aedui were advancing to the border with the Bellovaci in accordance with Caesar's arrangement with Diviciacus. At a council of the senior chieftains present with the army, the Belgians resolved to disperse and go home, each tribal contingent returning to its own lands, where they could easily be fed. Pledging themselves to come to the aid of any tribe that Caesar might attack over the coming months, the great army broke up. It did not do this in any ordered manner, individual leaders and groups simply packing up and walking off during the night."

  The Roman outposts reported the noisy departure of the Belgian army, but Caesar was suspicious that it might be a trap. The failure of the surprise attack against the Helvetii in the previous year may well have made him rather cautious about operations at night. At dawn he sent out patrols that confirmed that the enemy really were simply drifting away without any serious attempt to cover their retreat. The cavalry rode out under Pedius and Cotta, while Labienus followed them with three legions to provide close support. There was little resistance, and large numbers of Belgic warriors were killed and captured as they fled from the Roman pursuit. For the moment the great army had dispersed - it would take some time before the tribes were able concentrate their forces again. Caesar made sure that they did not have that time. On the following day he marched against the Suessiones, whose lands bordered on those of the Remi. By a forced march he reached one of their main towns at Noviodunum. (Like most of the other Belgic oppida mentioned by Caesar, its precise location is unknown, but it was most probably fairly near modern Soissons.) Believing from reports that the town had no defenders, Caesar sent his men straight into the attack. There were indeed few warriors to resist him, but the Romans had no ladders or other siege equipment and those few were able to repulse the attack. After this failure, Caesar made sure that the business was done properly and set the legionaries to making a ramp, siege towers and mantlets to take his men up to and over the wall. The town was not yet
blockaded, and numbers of warriors from the dispersing army took refuge within it. Their morale was shaky, however, and the sight of the Roman siege machines caused dismay. The Suessiones surrendered, winning favourable terms because the Remi interceded on their behalf. They gave up hostages from their leading families, including two of King Galba's sons, and handed over quantities of weapons - perhaps a token amount as a symbol of disarmament.1S

  Caesar needed to move on while the advantage was still with him and now attacked the Bellovaci. These similarly put up little resistance and swiftly surrendered. This time it was Diviciacus of the Aedui who spoke for them, pleading long-standing friendship between their two tribes. The recent hostility of the Bellovaci was blamed on a few chieftains who saw the Aedui's alliance with Rome as slavery. These men had now fled to Britain and could no longer influence tribal policy. Caesar happily granted the pleas and accepted the surrender on similarly lenient terms, although he did demand and receive 600 hostages, which was clearly far more than normal. In part this was because he wanted to honour Diviciacus and the Aedui, but it was also important to weaken the coalition facing him by removing as many members as possible. The high total of hostages makes it likely that most of the Suessiones' aristocratic families sent someone to Caesar's camp and this was clearly intended to ensure that they did not risk renewing the war. Throughout the Commentaries on the Gallic War there are frequent references to hostages, but never once does Caesar say what happened to any who came from tribes that broke their treaties with him. It would be surprising if most of these were not executed on such occasions. After thus dealing with two powerful tribes individually, Caesar next attacked the smaller Ambiani, who swiftly capitulated. Well over a third of the force that it was claimed the Belgians had mustered earlier in the year had now been defeated and the odds were turning in Caesar's favour. However, the easy victories of the last days were over and resistance was hardening.19

  THE BATTLE OF THE SAMBRE

  Caesar now drove north-west against the Nervii, the largest tribe still willing to fight.

  After three days the Roman column was about 10 miles away from the River Sambre, and captives revealed under interrogation that the tribal army was waiting on the far side. They had been joined by the Atrebates and Viromandui, and another tribe, the Atuatuci, were on their way. According to the Remi's estimates, the Nervii, Atrebates and Viromandui had contributed 75,000 men to the coalition army raised earlier in the summer, and Caesar gives the first tribe 10,000 more men in this battle. As we have seen, the reliability of theses figure is questionable, and their contingents had probably anyway been weakened by the earlier operations and further reduced by warriors who had not yet been able to join the army. Caesar's eight legions probably mustered somewhere in the region of 30-40,000 men, backed by several thousand cavalry and as many light troops. It seems likely that the Nervii and their allies had at the very least parity of numbers with Caesar's men, and probably a significant numerical advantage, although probably not as much as double the Roman numbers. The Belgians were determined to fight, and had evacuated their women, children and other non-combatants to places of sanctuary deep in inaccessible marshland. They also had information sent secretly by some of the Gauls and Belgians marching with Caesar as allies or hostages. These had reported that Caesar's normal order of march was for each legion to form up separately, guarding its own baggage train. This meant that the fighting troops were split up into eight main sections, with cumbersome lines of servants, carts and pack animals between them, which would have made it difficult to form a battle line.20

  Such a formation made the Romans vulnerable, and the Nervii had picked their ground carefully. As usual there can be no certainty as to the precise location of the battle, but a site within a few miles of Maubeuge seems quite probable. It is possible that the tribe had repelled invaders at this spot before. They evidently knew where Caesar would cross the river, which makes it probable that he was following a well-trodden route, used by the tribes for the movement of trade as well as armies. Low hills rose on either side of the river, which at this time of year was only about 3 feet deep and easily forded. On the far bank, the valley side was open for about 200 paces, but was then heavily wooded, allowing the warriors to wait in concealment. On the side from which the Romans were approaching, the ground was broken by lines of thick, high hedges, made deliberately by the Nervii to hinder raids by enemy horsemen. These were an obstacle both to movement and visibility, and were intended to send a clear message to raiders that once they crossed this point their attack would be resisted by a tribe proud of its martial reputation. Now they intended to give Caesar a demonstration of this and would launch an all-out attack as soon as the baggage behind the leading legion came into view."

  Battle of the Sambre

  The captives - presumably men brought in by the cavalry patrols and scouts that preceded the main army - had warned Caesar that the river crossing would be contested. As a result he changed the march formation, adopting what he claims was his standard deployment when there was a risk of encountering the enemy. After the screen of cavalry and light troops, the six experienced legions marched unencumbered by baggage, all of which was massed together and guarded by the two new legions who followed at the rear. On this particular day the Tenth was in the lead, followed by the Ninth, then the Eleventh, Eighth, Twelfth and Seventh. A party of centurions accompanied the forward scouting patrols and had the task of selecting and marking out the camp site for the night. The construction of a marching camp protected by a ditch and an earth wall formed from the spoil was standard practice for any Roman army in the field, and was the equivalent of modern infantrymen digging in at the end of a move. A camp took several hours to construct, but then offered security against sudden attack, and was laid out to a regular design, so that each unit knew its place. The centurions marked out a site on the hill on the near side of the river. When the main force began to arrive, the cavalry and light troops splashed through the water and formed a screen on the enemy-held bank. The bulk of the tribal army was hidden amongst the trees, but a few small groups darted forward and skirmished with the Romans. The Nervii had very few cavalrymen, and the auxiliaries easily held their own in the resulting combats, but took care not to pursue too far and enter the woods. As the legions arrived, they began the task of building the camp, packs were laid down, helmets, shields and pila piled, but it was normal for legionaries to keep their armour on while they dug. Each legate supervised the legion under his command, for Caesar had instructed them - probably as a permanent standing order - to remain with their men until the camp was complete. Small detachments of armed legionaries may well have been sent out as piquets, but there was no real effort to protect the labourers from a full-scale attack.

  In the previous year Caesar had covered the construction of a camp close to Ariovistus' army by keeping the first and second lines of the legions in battle order facing the enemy, while the cohorts of the third line dug. Napoleon and many other commentators have justifiably criticised him for not adopting a similar practice here. Caesar already knew that the enemy were massed somewhere across the river, and would have seen his cavalry and light troops skirmishing with them on the far bank. The Nervii and their allies were close and therefore an attack possible, but he may have judged it unlikely. The day was considerably advanced and the enemy had done no more than harass his outposts. Weeks before, when he had faced an even larger army, it had refused to attack across some difficult ground and the river felt like a secure barrier. Keeping a substantial part of his army under arms would slow the building of the camp - in 58 BC the cohorts of the third line had had to construct a camp for only two legions, not the entire army. Whether through a conscious decision or simple omission, perhaps brought on by complacency after the easy defeat of three tribes in the last weeks, Caesar took the risk of not protecting the legions as they worked. It nearly proved fatal."

  The Belgians displayed admirable discipline as they waited for the moment t
o attack. The leaders of the army - a Nervian chieftain named Boduognatus was in overall charge - had agreed that they would wait until the Roman baggage appeared. Even though this did not follow the leading legion as they had expected, the warriors remained calm and only when the concentrated train of the army came into view on the far side of the valley did they leave the cover of the woods and advance. The Romans' auxiliary cavalry and light troops could not hope to withstand a massed attack and quickly gave way. The Belgian line had been formed into tribal contingents under cover of the trees and surged quickly down the slope and across the river. Some of their order was lost in the process, and the hedges on the far shore probably encouraged the line to break up even further. For all that, they were still better prepared for battle than the Romans, who struggled to form any sort of a fighting line. The battles against the Helvetii and Ariovistus - and indeed most large encounters in this period - were carefully prepared and anticipated affairs, with hours spent carefully deploying the lines and encouraging the troops for the clash to come. This time it was different and: `Caesar had to do everything at the same time: to raise the standard, which was the signal to stand to arms, to sound the trumpet call which recalled the soldiers from work, to bring back the men who had gone further afield in search of material for the rampart, to form the line of battle, to address the soldiers, and to give the signal for battle.'23