Very soon after the flight of the great orator, Cæsar, who had been watching with his army the proceedings within the city, started for his province of Gaul. The country which was to be the scene of his labors as governor, and in which through successive campaigns his reputation in generalship was to be made, was larger than modern France, for it extended to the Rhine, the Alps, and the Pyrenees. Only a part of it was familiar to the Romans, and for this reason one of the most striking proofs of Cæsar’s skill as a commander is the ability and certainty with which he penetrated into regions unvisited before and therefore unfamiliar to him except by the hearsay stories of the casual traveler. The province had originally been occupied by the Romans in the struggle with Hannibal, because it secured their land communication with Spain. In its southern part it was well developed and civilized, but the limit of Roman rule northward was marked by the valley of the Rhone, and the famous city of Lyons had not yet been founded, which was later on the headquarters of Roman power in Gaul.
Much trouble was being experienced from Germanic invaders farther north, who were crossing the Rhine and were in great numbers occupying the fertile lands to the east of them. The Gauls themselves had no cohesive power of resistance; they were constantly quarreling among themselves, and it seemed only a question of time when the Germans, uniting with the Gauls, who were certain to become subject to their rule, would overwhelm the peaceful and civilized inhabitants of the Roman province. The situation required immediate attention, for the Ædui who lived between the Loire and the Saône were calling on the Romans as allies for help and protection against their neighbors, other Gaulish tribes, who with the aid of the German king, Ariovistus, were threatening to take their land. Besides, it was reported that the Helvetic and the German peoples were contemplating a migration on a large scale, induced to leave south Germany by the prospect of finding better lands farther west.
The country as a whole was in a state of unrest; the unconquered mass of the free tribes, extending from the fringe of Roman occupation in the south to the North Sea, might easily become dangerous to the countries under Roman occupation on the other side of the Pyrenees and the Alps. Up to the time of Cæsar’s advent, the government at Rome had shown singular apathy; a few resolutions had been passed, directing that the allied tribes should be aided, but no additions were made to the army in the province. The emotional temperament of the Gauls made them subject to quick changes in their point of view; unless something were done quickly, even the allies of Rome would have to be counted on the other side. It was easy for them to drop their present allegiance, for they were as a mass a servile population, guided by an aristocracy of nobles or knights, and by a widely extended and mysterious guild, the Druids, who each year held a solemn assembly in a sacred place in the center of the land.
The general difficulties of coping with the situation were great when Cæsar took command, but the special details of the position as it confronted him increased the obstacles in the way of prompt action. There was but one legion beyond the Alps; the other three were far away in Aquileia at the top of the Adriatic. It was fortunate for him that he could draw on the reserves of Cisalpine Gaul, the richest part of Italy, the province which extended over the plains of Lombardy to Tuscany. This province was filled with a hardy race of yeomen cultivators, a mixed population, having its origin in the conquered Celtic tribes and in genuine Roman colonists.
Nowhere else could there be found a better recruiting ground for the legions, and nowhere also, on account of the general intelligence of the inhabitants, would the personal qualities of a general find a more immediate response. The tactfulness of Cæsar had already been put to the test in the arena of political life; he had learned how to make friends and to hold them. Apart from the technical gifts of military art, the personal charm of Cæsar’s character was a great factor in securing for him an army made up of devoted troops and officers. They trusted him, and they were held to him as a leader, because he seems from the first to have been able to establish close relations of a spontaneous and genuine type with those who were under him. His army was not a mere fighting machine, but an organism reflecting the individual driving power and coolness of the man who led it.
The series of campaigns in Gaul begins with Cæsar’s successful blocking of the migration of the Helvetii. All that is known of the details of the strategy employed by the Romans is derived from Cæsar’s own report, which has been frequently criticised as intentionally obscure and misleading. It must be remembered that the famous commentaries on the Gallic wars were hurriedly dictated, and were meant to tell the public what the commander-in-chief wished them to know and nothing more. For example, many modern authorities are agreed that the numbers of the migrating Helvetii are very much overestimated by Cæsar and that the real purpose of their migration was artfully concealed. Napoleon, who was a past master in falsifying military records, declared that the campaign against the Helvetii as narrated by Cæsar was incomprehensible.
The real situation in Gaul prior to the migration seems to have been as follows. As we have said, Ariovistus, the German king, was in control of the central part of the country. This overlordship was burdensome to the Gauls, who paid him a yearly tribute. A prince of the Ædui, Divitiacus, had turned to the Romans for help, but his request was rejected, for Ariovistus, during Cæsar’s own consulship, had been acknowledged as king and formally declared an ally and friend of the Roman people. There was another party among the Ædui, led by Dumnorix, the brother of Divitiacus, who favored throwing off the German yoke, and urged a general uprising of the Gauls, unassisted by the Romans.
Not far away from Æduan territory were the Helvetii, who were independent of the rule of Ariovistus, and with them the autonomous party among the Ædui entered into friendly relations in order to secure them as allies against the Germans. The Helvetii were to be persuaded by their leaders to migrate to western Gaul, and it was arranged that, when the whole tribe was slowly passing through the land of the Ædui, there should be a rising against Ariovistus. The Ædui could count on the assistance of the Helvetii, because as future occupants of Gallic territory the immigrants would have no desire to be dependents of the German king.
This situation and this program were known to Cæsar before he left Rome, for he was in communication with the pro-Roman party among the Ædui. It was of course his object to frustrate this plan of driving out the Germans without the help of Rome, because it was to his interest that Roman overlordship should take the place of German control. The request of the Helvetii to be allowed to pass peacefully through Roman territory came just in time. It gave Cæsar the opportunity of defending the frontier and strengthening his army.
As soon as the Helvetii were refused a passage through the Roman province, they started directly for the land of the Ædui, crossing over the Roman territory, and so they abandoned the fiction of a migration to the west. In the meantime, by the liberal use of money, the pro-Roman party among the Ædui had got the upper hand. Accordingly when the Helvetii, whose rear division had been attacked by Cæsar as they were crossing the Saône, reached the land of their would-be allies, they were treated as enemies by the Ædui, who were now calling on Cæsar for help to resist the invaders. The Helvetii, willing to return, desired to come to terms with the Roman general, but they refused to accept the Roman conditions as to hostages. They started to retrace their steps by following a more northerly course on their return in order to take advantage of the mountainous country, as a protection against an attack on the part of the Romans.
Cæsar followed warily; his own troops were indeed strengthened by Æduan cavalry, but these, on the first engagement, had fled before the enemy. It was obvious their loyalty could not be depended upon, and significant, too, that Dumnorix was in command. When an attempt to surround the Helvetii with two Roman legions failed, Cæsar withdrew to Bibracte, the Æduan capital, to replenish his army and probably to prevent the defection of his allies. The Helvetii might now have returned to their old home unmolested, but they were embittered against the Romans, who had shown constant hostility to their movements, whether they advanced or retreated, and they were quite willing to treat with the patriotic party among the Ædui, who asked them now for help against the Romans. They turned back therefore, with the purpose of attacking the Romans as they were marching towards Bibracte.
The actual number of the Helvetii engaged in this operation cannot have been very great, for their wagon train was in a very short time collected, formed, and turned into an improvised citadel. Their movements before, during, and after battle show that the number 368,000 given by Cæsar is enormously exaggerated. Altogether, including allied forces, Cæsar’s army may be reckoned at 40,000 men. There were six legions (36,000 men) and allied cavalry to the number of 4000.
When the Helvetii approached, the brunt of the fighting was assigned to four legions of veterans; the rest, the fresh recruits and the allies, were placed behind the line of battle and directed to protect the camp. As the Helvetii attacked the four legions, who were advantageously stationed on the slope of a hill, they were thrown back; but, as the legions advanced, these in turn were vigorously attacked on their flanks. The battle was hotly contested, the Romans taking the offensive both in the front and on the sides. Slowly the enemy withdrew, and it was dark before the Roman army took the massed wagons by assault. After the victory, Cæsar remained on the field of battle for three days. The Helvetii fled towards the east and a few days later surrendered, most of them being sent back to their old homes. The Helvetian overthrow was a useful stroke; it made a decided impression on the Gauls, who were now able to take the measure of the new commander of the Romans.
The next move was to break the power of Ariovistus. Cæsar represents the suggestion as coming from various Gallic deputations, who besought him to help them cast off the German yoke. But it is obvious that the presence of Ariovistus in Gaul was incompatible with the purpose of Cæsar to subjugate the entire country. All negotiations with the German chieftain proved futile; he insisted on keeping the Gallic tribes as his tributaries, and simply asked to be let alone.
Cæsar took his army to the east and came into contact with the Germans in the neighborhood of Belfort or in southern Alsace; it is impossible to determine the locality with precision. Ariovistus collected his wagons into a fortified camp on an elevation a short distance from the position of the Romans, using his advantage to break up by cavalry sorties the Roman line of communication. His plan appears to have been to force the Romans to withdraw and to attack them on their march. The German leader took full advantage of the mobility of his troops, and his cavalry proved too strong for the Gallic horse on the side of the Romans. All attempts to draw Ariovistus from his camp failed, until Cæsar divided his army, placing two legions in a fortified position, where they could more efficiently protect the line of communications. This smaller camp Ariovistus tried to take by storm, and failed.
When the main Roman army advanced, and began to threaten the wagon citadel of the Germans, Ariovistus determined to give battle. The battle itself was won through the superior discipline of the Romans; once during its progress the left wing was in danger, but it was saved by the prompt action of the younger Crassus, who was in command of the cavalry. Cæsar with the right wing carried all before him. As to the numbers engaged, it was Napoleon’s opinion that the Germans were not stronger than Cæsar; the probability is that they were weaker. Ariovistus’ whole army, though with it he controlled a large part of Gaul, need not have been more than 20,000 men. They were, of course, a better trained fighting force than anything the Gallic tribes could create, and it was not difficult, using the divisions among the Gauls, to establish an effective overlordship with a small, well-disciplined army.
Apparently the bulk of the German army was destroyed; Ariovistus, however, succeeded in making his escape beyond the Rhine. The defeat of the Germans had important consequences; before the opening of the campaign against Ariovistus, news had come from the north that the Suevi, an important German tribe, were about to move across the Rhine. The knowledge of the fate of Ariovistus forced them back again into the depths of Germany.
During the winter Cæsar crossed the Alps to attend to the administration of the Cisalpine province, leaving his troops quartered in Gaul under the command of his trusted lieutenant, Labienus. He raised two new legions, and when he returned northward it was already plain that the pacification of the country was far from complete. The Gauls feared the expansion of Roman power, and there were rumors of an uprising to be led by the tribes of the Belgæ. Cæsar marched directly to the danger spot, and taking advantage of tribal jealousies, induced the Remi, whose territory lay between the Maas, the Oise, and the Maine, to accept the alliance and protectorate of Rome. (57 B.C.)
This was a wise move, for it was clear from reports on the spot that the whole Belgic confederacy, representing the most warlike of the Gallic tribes, were up in arms. The fate of Ariovistus, the year before, had shown that the only way to resist the extension of Roman rule in Gaul was by tribal combination. The Belgæ thoroughly realized their danger, and when Cæsar passed their frontiers, they opposed him with a large allied army composed of contingents of all the neighboring peoples.
The great difficulty was to keep such large masses of men together and to provide them with food. In the time of Marius, the Germanic invaders, the Cimbri and the Teutones, in order to secure provisions as they went, had divided into several smaller groups, each one of which was beaten in detail by the Roman general. Cæsar’s strategy was to be governed by the same principles; he meant to wear the Belgæ out and to refuse to give battle until they had lost their unity, until each dissevered fraction might be drawn into action without support from the rest. Cæsar having recruited two new legions, in all there were eight. Besides, there served under him a variegated band of allies, Numidians, Cretans, men of the Balearic Islands, and Gallic cavalry.
Altogether the Roman fighting host may be reckoned at fifty to sixty thousand men, with camp followers, perhaps nearly one hundred thousand in all. To keep such a body in the field for a considerable time meant a carefully organized system of transportation and economic equipment. A strongly fortified camp was constructed on the north bank of the River Aisne, where the soldiers were kept in good discipline. The remains of extensive fortifications, in the form of ditches eighteen feet wide and nine or ten feet deep, and a wall with palisades twelve feet high, were found on the site of Cæsar’s camp by the archæologists who worked under the direction of Napoleon III.
The camp was in the country of the Remi, who had, as we have mentioned, become allies of the Romans; it was their town Bibrax which the Belgæ first attacked, hoping to induce Cæsar to leave his fortified position to repel them. He remained, however, where he was, sending sufficient help in the way of defensive artillery to enable the townsmen to defend themselves and to force the Belgæ to give up the siege. They then turned to attack the Roman camp. Cæsar drew up his army, but neither side had any desire to come to close quarters, as in front of the camp there was a considerable stretch of swampy ground. The Belgæ then tried to cut off the Roman line of communications, but this involved crossing the Aisne, and its banks were closely watched by Cæsar’s men. A few horsemen and war engines were sufficient to deter them from making the attempt.
If the Belgæ had crossed with their whole army, they could have carried out their purpose; the Roman communications would have been broken, but the Romans could have gone ahead, and the Belgæ, outside of their own land, had no way of maintaining their supplies. The only thing to do was to surround the Roman camp from all sides and starve it out. Even with their superior numbers, which Cæsar gives as 306,000, this was a difficult operation, for the enveloping lines, owing to the country being traversed by two rivers, would have been large. In any case the Belgæ recognized that they could not keep the field long, and when they heard that Cæsar’s allies, the Ædui, were invading their country, they decided to withdraw, the confederated tribes engaging to help one another if Cæsar’s army invaded their territory. The retreat of the Belgæ was so unexpected that at first the Romans took it for a feint meant to provoke them to leave their camp.
As soon as the news was well authenticated, the cavalry pursued the retreating barbarians, keeping up a series of irritating attacks. The Belgic strongholds surrendered soon after; only three tribes, the Nervii, the Viromandui, and the Atrebates, tried to strike a blow for Gallic freedom. They fell upon the Romans, while they were arranging to encamp in a woody country on the Sambre, and caused almost a panic. The allied troops fled in confusion, but the legionaries held their ground, getting themselves in line, and as they were far superior in numbers to the Nervii, they soon got the upper hand of them, although there was some sharp fighting and for a time two of the legions were hard pressed. It was part of the Roman general’s strategy not to face a superior force. This point is apparent in the previous campaigns, but, as a military writer, Cæsar had no scruples in manipulating his figures for popular consumption. When the Nervii made peace unconditionally, they represented themselves, according to Cæsar, as having only 500 men left out of an original 60,000 capable of bearing arms; a few years later they appear again in the Commentaries as having a considerable army. They also sent a contingent of 5000 to Alesia at the close of the Gallic war. Probably a just estimate of the fighting force of the Nervii would give them 30,000 men, because the whole population of the district could hardly have been more than 150,000 souls. They occupied a territory of four hundred square kilometers, and with the slight density of population in Gaul, they could not have numbered more than the figures given above. Even in the Italian peninsula, which was more thickly settled, there was altogether a population of not more than three and a half millions and a density of only twenty-five per square kilometer. The Roman legions who opposed the Nervii in this last fight numbered at least 40,000 men.
Dwelling east of the Nervii were the Aduatuci, said to be descendants of the survivors of the former Cimbri and Teutones, whom Marius had destroyed. They had promised to help the Nervii, but had come too late for the battle. Now they withdrew to their chief fortress, but when they saw themselves being enveloped in the complicated and scientific siege works of the Romans, their hearts failed and they surrendered before the final assault was made. What they had not been able to do openly they hoped to accomplish by treachery, for they reserved a part of their arms, at the time they made their submission, and when the Romans were off their guard at night, made a sudden attack upon them. They were defeated with heavy loss, and the next day, in order to make an example of them, Cæsar sold the whole tribe, men, women, and children, into slavery, 53,000 souls in all.
After the Belgic campaign was over, Cæsar laid plans for the further expansion of Roman control in Gaul by sending one of his lieutenants to Armorica, modern Normandy and Brittany, to secure the submission of the inhabitants. Moreover, seven legions were placed in winter quarters along the Loire, ready to use the stream to transport themselves to the territory of the Veneti, the chief tribe in the west of Gaul. (56 B.C.)
The announcement of Cæsar’s great success made a profound impression in Rome; new and unknown domains were being annexed, and the people were granted an unprecedented space of fifteen days for a public thanksgiving. During the winter the general himself took up the detailed work of governor of the Cisalpine province, and also made a tour of Illyria, which had been previously unvisited by him. It was filled with a hardy and brave population and might well be used for drawing auxiliary troops for his army.
In Gaul the situation of affairs showed that the people of Armorica could not be depended upon, though they professed loyalty to the Romans. Young Crassus, who commanded a garrison encamped at the mouth of the Loire, when he found his soldiers suffering from lack of supplies, sent some of his officers to collect provisions from the neighboring districts supposedly friendly. The Veneti seized these men, and refused to give them up except in exchange for their own hostages in the hands of the Romans, and they proceeded to bind themselves together for common action, showing their desire to repudiate the sovereignty of Rome. Cæsar’s reply to the challenge was to order the preparation of a fleet of ships to be put into service the following summer against the Veneti, whose chief seats were along the sea coast.
It was not possible for Cæsar to direct these operations in person, for affairs in Rome demanded his presence on the southern side of the Alps. Clodius had mismanaged the affairs of the democratic party in Rome, had proved headstrong, had alienated Pompeius, and had been unable to prevent the return of Cicero from exile. The cause of the senatorial oligarchy was progressing, and a danger point was reached when Crassus drew away from Pompeius, of whose popularity he was jealous, and when Pompeius himself felt that his talents and his position as conqueror of the East were not being sufficiently recognized. Cato, too, was returning from Cyprus, and could be relied upon to give the triumvirs trouble in his rôle of professional obstructionist.
As there was talk already in Rome of the recalling of Cæsar, a consultation between the triumvirs was imperatively needed. Lucca in Tuscany was selected for the place of meeting, which took place in April, 56. A great crowd of officials, magistrates, and senators were present to receive orders from the triumvirs or to hear particulars of the conference. Cæsar by his diplomacy managed to remove the causes of estrangement between Crassus and Pompeius, and the details of a common policy were arranged. By the conference at Lucca, through the adroit manipulation of Cæsar, the old combination that had begun to work haltingly, owing to the estrangement between Crassus and Pompeius, and also to their common lack of political acumen, was re-established and its details settled.
The main thing was to muzzle the Senate; with this done, it would be safe for Pompeius and Crassus to carry out their plans for securing an important province each, together with a military command for a long term of years. The arrangement was that the other two triumvirs (Cæsar of course returning to finish the subjugation of Gaul) should be Consuls in 55; and after their year of magistracy was finished, Pompeius was to have the two provinces in Spain, and Crassus was to go to the East, where there would be a chance of achieving military distinction in a war with the Parthians. In the local affairs of Rome care was taken that Clodius should be kept from continuing his line of irresponsible action, and Cicero was drawn into the sphere of Cæsar’s influence by his brother being given a subordinate military command in Gaul.
Cæsar, when the conference was over, soon returned to the front, to deal with the Veneti in such an effective way that by their example the Gallic tribes might be taught the risks of braving the power of Rome. Divisions of the army were sent to various points of Gaul, where it seemed likely there might be sympathetic uprisings of the populations in favor of the national movement, led by the tribes about the Loire. The Veneti had against them Cæsar himself, and the problem of their subjugation offered some novel difficulties. Their fortified places were usually on headlands; sometimes inaccessible from the mainland except by ship. The country was cut up by many estuaries, and the Veneti, who were practised sailors, showed great mobility in their movements. They withdrew from one post to another, easily cutting themselves off from attack as the Romans, who were not familiar with the country, advanced to meet them with the hope of forcing a decisive engagement. Their power could be destroyed only in a naval battle, and it required both patience and ingenuity on Cæsar’s part before his men could be trained to meet the enemy in their own waters, or even before a fleet could be built suitable to overcome the special difficulties of navigation on the shores of the Bay of Biscay, so unlike the conditions in the Mediterranean. The fleet of the Veneti was finally destroyed; their ships were rendered helpless when the men on the Roman fleet cut their rigging with long poles having at the end sharp hooked knives, and boarding parties disposed of the warriors on the decks. Many of the brave tribe were put to death when they submitted, and the rest were sold as slaves.
In the meantime the operations of the subordinate commanders had been successful, and conspicuous results had been reached in Aquitaine, where the younger Crassus had brought all the tribes to accept Roman sovereignty. Indeed the only failure to be registered this year was Cæsar’s own expedition in the far northern part of Gaul between the Somme and the Rhine, the dwelling place of the Morini and the Menapii. These tribes took refuge in their forests and could not be dislodged, and even some incidental defeats failed to break their obstinacy.
The new year, as it opened, with news of a German invasion on a large scale, brought fresh anxieties to the commander. It was told him that warlike tribes living in and about the Thuringian forest were on the move towards the west, and that others had even crossed the Rhine, dispersing the Gallic tribes in their progress. In Gaul there was a disposition in some quarters to welcome them as deliverers; already some of the Gallic tribes were in communication with them on a friendly basis. (55 B.C.)
Cæsar marched to meet the Germans, and in a conference with their leaders told them they must leave Gallic territory, at the same time offering to make an arrangement by which they could receive land on the right bank of the Rhine. They seemed disposed to accept these terms, but soon hostilities were precipitated because, while the terms were being discussed, the Germans attacked some of the Gallic cavalry attached to Cæsar’s army. The Romans moved suddenly, and according to Cæsar’s own account, butchered in cold blood men, women, and children to the number of 430,000, a hearsay number of course, but there is no reason for doubting that there was a massacre. No Roman was killed and few were wounded. Even in Rome, notoriously insensible to deeds of blood, this wholesale butchery caused disgust. Cato proposed that Cæsar should be given up to the barbarians as an act of justice. But the Senate contented itself with decreeing honors for the victory, although it was proposed, but not carried, that the operations in Gaul should be investigated by a commission.
To finish up the moral effect made on the Germans by the massacre of their kinsmen, Cæsar built a trestle across the Rhine, transported his army into German territory, and for a short time his soldiers were employed in laying waste the country contiguous to the river. He had no intention of penetrating to the interior of the country, and soon returned to Gaul, after destroying the bridge he had built.
This year’s campaign had been marked by daring adventures; it was to have a spectacular close in the expedition to Britain, an island known in a general way to traders from Gaul, but never yet visited by a Roman official or by a Roman army. Cæsar affected to believe that resistance to Roman rule in Gaul was being supported from Britain. In any case a protectorate of the island seemed to offer great material advantages, for exaggerated reports were in circulation as to its wealth and fertility. The expedition was only a partial success. A few tribes made their submission, but the troops had to be hastily withdrawn, because Cæsar desired to be back on the mainland before the equinoctials set in, as the fleet had already severely suffered in a storm.
In the winter preparations were made on a large scale for a second crossing, a large body of transports being prepared and collected at Portus Itius (perhaps Wissant, near Cape Grinez). The troops in the meantime were carefully trained in handling newly constructed vessels specially planned for the waters of the narrow seas. During the winter the periodic signs of disaffection among the Gauls were again plainly visible, this time the Treviri were intriguing with the Germans. An advance in force from Cæsar was needed to put a check to the rising hopes of the anti-Roman party, whose chief, Indutiomar, was forced to give hostages for his good behavior. Much discontent was caused by the necessity of sending contingents to the army; besides, the legions were a burden on the food supplies of the land. The feeling against foreign control grew so strong that Cæsar determined to take some of the Gallic chiefs with him to Britain, to keep them under personal observation. Dumnorix, the Æduan, tried to secure common action among all and to induce the other chiefs not to embark. Only Dumnorix, however, withdrew when the fleet was about to sail. A party was sent back to pursue him. When he resisted, he was slain.
The second expedition to Britain was on an unprecedented scale. There were five legions, two cavalry troops, and an armada of 800 vessels to carry them. The British tribes withdrew from the coast, and there was some fighting, as the Romans made their way inland to attack various British strongholds. Some of the tribes submitted, but the Roman victories were more apparent than real; the camp around the fleet was attacked, and as the army returned, it was continually harassed by an active enemy, who dogged each stage of the march, but refused to come out and fight in the open. The chief result of the invasion was the collection of reliable information about the people and their customs. The island was not occupied or formally conquered for nearly a century. The captives that were taken were brought over to the continent and sold as slaves. (54 B.C.)
When the expedition returned, the troops were distributed through Gaul in winter quarters as camps of observation, not more than a hundred miles from one another; Cæsar’s own headquarters being at Amiens. The scene of the first disturbance was in the northeast; a Roman garrison on the march from one camp to another was cut off, and only a few stragglers were left to tell the tale. Cicero’s brother Quintus, the commander of another garrison, was attacked, and no message could be got through the hostile tribes of the Nervii to tell Cæsar of his desperate straits. Finally news was carried by means of a Gallic slave whose master, a Nervian refugee, promised him his liberty if he were successful.
Cæsar, with one legion and with a division of horsemen, arrived just in time to save the beleaguered garrison. The Gauls were severely handled when the Romans pushed through their lines to reach Cicero’s camp. The news of the relief caused dejection among the other Gallic tribes, who were about to attack isolated Roman garrisons. Labienus alone had trouble with the Treviri, but managed to ward off the blow, inflicting upon them in turn a crushing defeat, and slaying their leader, Indutiomar. The rest of the winter and summer campaign was spent in various expeditions directed against the Gallic tribes whose loyalty was suspected. It was designed to make a special example of the Eburones, who had cut off the Roman legion the preceding year. They were doomed to destruction, and the neighboring tribes were invited to come and enjoy the plunder. Some of those who came preferred to attack the Romans first, and Cicero’s camp again fared badly by a sudden raid, made by the Sigambri, a German tribe, who had crossed the Rhine, invited by the prospect of plundering the Gauls. This mistake confused the whole original scheme, and it resulted in the escape of the leader of the Eburones, Ambiorix, an implacable foe of Rome.
When the winter of 53-52 came on, Cæsar’s sojourn in the Cisalpine province was passed during a season of much anxiety. Rome had been disturbed by factional fights between Clodius and his opponent, Milo, in which the popular demagogue met his death. There had been a drawing together of the senatorial party, and Pompeius, who was now looked upon as the chief bulwark against anarchy, had been intrusted by the Senate with extraordinary powers, enabling him to call for a general levy of men of military age throughout Italy. Julia, the wife of Pompeius, was dead, and with her vanished the one strong personal link between the two triumvirs, for Crassus had perished in the East fighting against the Parthians. The news of the troubles in Italy spread rapidly in Gaul, causing the restless tribes there to believe that Cæsar would be kept on the southern side of the Alps, and that, with the commander-in-chief away, there would be no trouble in bringing about a successful revolt, provided there were common action throughout the whole country. The essential condition was to unite all the Gauls against Roman control, and this had already in a large measure been accomplished by the king of the great tribe of the Arverni, Vercingetorix, now at the head of a confederation extending over the whole of the central part of the country. It was difficult to overcome the particularistic tendencies of the Gauls, but this new chieftain at least understood the difficulties and made a brave effort to counteract them. He showed also a sense of the strategical needs of the situation by advising the Gauls to make use of their superiority in cavalry and to cut off the Roman communications; another feature of his scheme was to lay waste the country and force the Roman garrisons to withdraw as they were gradually starved out.
A necessary part of the program was the fighting of a decisive battle on a large scale. Vercingetorix had the men at his command, for he had won over the Ædui, who from the first had aided the Romans in their conquests. Cæsar’s plan was to take the various tribal strongholds one by one; he succeeded in the case of Avaricum, the capital of the Bituriges. He then sent Labienus against Lutetia with four legions, while he advanced with six to lay siege to the chief city of the Arverni, Gergovia. Cæsar’s army was not strong enough for the task; the plan of attack failed, and the Roman legions were saved only by a quick junction with Labienus.
The whole army was soon withdrawn from central Gaul in order to protect the Roman province from attack and also to secure for Cæsar a position where he could establish a fortified camp, from which it would be difficult to be dislodged, and where he could depend upon a regular source of supplies. He selected a place on the Saône, where he could threaten the Æduan territory and be so protected that it would be dangerous for Vercingetorix to follow him. On the march the Romans were vigorously attacked by the Gallic cavalry, but, as they had with them a detachment of German horse, they were beaten off, and the Romans quickly turned the tables, pursuing the Gallic army and finally enclosing it in a hill town, Alesia (Alise Ste. Reine).
Preparations were now made for a long siege. It was a complicated affair, because Cæsar had to provide against attacks both from the beleaguered army and from the Gauls, who were hastening to aid their natural champion. The lines of contravallation were sixteen kilometers long, those of circumvallation twenty; the space between the Roman army and the town was filled with artificial obstacles, meant to prevent the successful use of infantry. The force under Cæsar numbered about 70,000 men and included eleven legions. Cæsar reports that there were 80,000 men imprisoned in Alesia, while to the Gallic relief army is assigned 250,000 infantry and 8000 cavalry. Probably there were not more than 20,000 men altogether in Alesia, for provisions were scarce. This is the number that Napoleon I would give to the inclosed army, and he further remarks that the relief army in its manœuvering and in its camping operations behaved as if it were equal, not superior in strength, to its adversaries.
Cæsar had five or six weeks of leisure before the relieving army appeared. The first part of the decisive engagement was marked by a cavalry battle, in which Cæsar’s German horse proved superior to the Gauls. Then a night attack on the inclosing lines was tried and failed. A daylight struggle afterwards took place along the weakest part of the Roman fortifications, Vercingetorix and the relief force making coincident attacks. The Gauls from the outside were driven off by a skilfully delivered movement on their flank, executed by Labienus, which forced them to withdraw, and at the same time Vercingetorix moved back into the city, and soon recognizing his hopeless position, surrendered. The fall of Alesia marks the completion of the Gallic wars. The spirit of the Gauls was broken; there were afterwards various punitive expeditions, but with the collapse of the great rebellion the country became pacified and accepted its position as a Roman dependency.