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.
IV
THE BREAK WITH POMPEIUS AND THE SENATE
Cæsar’s government of Gaul was now drawing to its close. He had added to the Roman dominions a territory larger than the two original provinces assigned to him. The question now was, what next? The precedents on this point were clear enough; they were written large in the lives of other recent conquerors, Marius and Sulla. But the senatorial party had no intention of allowing Cæsar to return to Rome with a free hand; it was to be a struggle between the self-interests of a narrow oligarchy and a clear-headed effort to attain personal control of the machinery of the government. On neither side was regard for legality given much weight. Both Cæsar and the senatorial party used without scruple illegal means; both at the same time claimed hypocritically to represent the side of law and order.