In a series of brilliant campaigns, Caesar subdued Gaul and the Germanic tribes and made incursions into Britain. Military achievements and political ambition were interwoven in Caesar’s character, and in 49 BC he lead his legions across the Rubicon to drive Pompey from Rome.
■ Ancient Authorities
We have now reached a chapter in which biography and autobiography may readily be identified with history. Caesar’s record of his Gallic Wars is the best known of his writings and is of particular interest to British readers, as it describes the first Roman military expeditions to Britain. The narrative of the Gallic Wars spans the period of 58 to 52 BC inclusive, and each of its seven books corresponds with a year in this period. To Caesar’s seven books, his officer Aulus Hirtius added an eighth, which brought the historical record up to 50 BC. Caesar’s account of the war (49 BC) which, after his return from Gaul, he fought against Pompey is given in the three books of his Commentaries on the Civil War. The story of his military career is then carried further by an anonymous history of his eastern campaigns, ending with the battle of Zela against Mithridates’ son in 47 BC. This work may also have been written by Hirtius. Another anonymous account describes Caesar’s victorious war in North Africa (47–46 BC), where Cato had joined other surviving Pompeians. A third narrative from an unknown hand relates to the last of Caesar’s wars, fought against the sons of Pompey in Spain and leading to the final victory at Munda in 45 BC. Unfortunately, the Spanish War is not intelligently or clearly written, although the writer, perhaps a junior officer, seems to have been an eyewitness of operations which he describes.
Apart from Plutarch’s Life, we have a biography of Caesar by Suetonius (Gaius Suetonius Tranquillus), who was probably born in AD 69 and survived well into the second century, holding secretarial positions under the Emperor Hadrian, posts to which he was perhaps helped by another distinguished writer, the younger Pliny (Gaius Plinius Caecilius Secundus). Almost the only extant work of Suetonius is his Lives of the Caesars. It contains 12 biographies, beginning with that of Julius Caesar and continuing with the line of Roman emperors who followed, as far as Domitian.
As to Julius Caesar’s political career before his appointment to command in Gaul, much is to be learnt from Cicero and Sallust, but despite the biographies of Plutarch and Suetonius, our knowledge of him as a young man is fragmentary and imprecise. While Sulla’s energies were concentrated on meting out retribution to the Marian party in Italy, Mithridates, temporarily subdued, had once more become active, and Caesar, then in the East, enthusiastically participated in military action against him. While raising a fleet in Bithynia, he was suspected of a homosexual relationship with the Bithynian king, but Suetonius, who records this circumstance, was notably addicted to scandal. While still a young man, Caesar achieved military distinction in the eastern wars and after an action at Mitylene was awarded a civic oak-leaf crown for saving the life of a fellow-soldier. Like Crassus, he seems to have abandoned the military life for politics and then to have realized later that, in the world in which he found himself, military command and victory were prerequisites of political success.
Apart from war and politics, Caesar was deeply committed to the cultivation of literature. He had interrupted his earlier career in order to pursue literary studies at Rhodes, and he wrote books on literary criticism, now lost. In these works, he is known to have advised the avoidance of unusual or recondite words, and his own war commentaries are models of lucidity, because he practised what he preached.
■ Political Background
The clan of the Julii claimed to be older than Rome itself. On the other hand, Caesar was connected by marriage with leaders of the Popular party. As a result, he could command the support of the mob, while he talked to aristocrats on equal terms: against which it must be admitted that he was distrusted by both parties. His early career was certainly not calculated to inspire confidence. He was a manipulator of political violence, an apologist for disreputable causes, an unscrupulous demagogue of the kind which Rome already knew only too well – except that his Latin was impeccable. His dress was fastidious and effeminate, and anyone could be pardoned for believing stories about the king of Bithynia. Notwithstanding, Suetonius cites an impressive list of distinguished Roman ladies whom he is said to have seduced, including the wives of Pompey and Crassus.
To promote his political plans, as well as his personal living standards, Caesar borrowed heavily from Crassus – who ran a kind of political finance business. This, of course, placed Caesar’s demagogic art at Crassus’ disposal, and was liable to involve the demagogue in cases against which his natural sagacity would otherwise have warned him. Catiline’s conspiracy may have been an instance of such involvement. At the same time, Caesar possessed an insight into realities which enabled him to see, as Cicero was unable or unwilling to see, that the real rulers of Rome were Pompey and the army which he could at any time summon to his support. All the constitutionalism which had survived as outworn tradition or had been violently imposed by Sulla was a mere facade. If the constitutional illusion persisted, this was due only to Pompey’s reluctance in his political role. That great man’s ambition was purely professional. He wished at heart merely to be Rome’s leading general, not its autocrat.
With financial help from Crassus, Caesar obtained a military command in Spain in 61 BC. Here, the pacified Roman province still needed to be protected against the hill tribes of the northwest, and there was abundant scope for military action, Caesar proved to himself what he must have suspected: the military ability which he had shown in the East as a young man had not deserted him on the threshold of middle age. Spoil and slaves were the ordinary perquisites of successful war. One has furthermore to take into account the normal extortionate practices of a Roman governor. Caesar returned to Rome, once more a rich man, free from the burden of his debts to Crassus. He must now also have realized that he had it in him to be a general at least as great as Pompey.
In 60 BC Caesar, as consul, quietly and confidently disregarded the Republican constitution and left only a few opponents helplessly remonstrating. Power was now in the hands of Pompey, Caesar and Crassus, and the sources of their power, exerted in person or through agents, were military force, mob rule and money. By refusal to make reasonable concessions to any of them, the Senate drove its three potential enemies into alliance. Yet it must be admitted that any concessions could easily have proved the thin ends of unconstitutional wedges. At least, the triple alliance, while it lasted, meant peace. If the constitutionalists had chosen to exploit jealousy among the opponents of their authority, they might have preserved some measure of independence, while making Italy once more the theatre of war between armed contenders. From the point of view of Republicans like Cicero or Cato, the situation had to be seen as one which admitted no happy issue.
■ The Helvetii and Ariovistus
It may be asked whether Caesar’s conquest of Gaul was in fact a great achievement in the Roman national interest or whether it was simply a means to personal prestige and political power at home. The same question may be asked of many Roman military exploits in the first century BC. In the instance of Crassus’ disastrous Parthian expedition, the motives were obviously personal, while of all commanders at this time, Pompey was probably the most ready to await rather than create his opportunities. Caesar’s operations in Gaul were more demonstrably directed towards the security of Rome than Crassus’ eastern campaign would have proved, even if it had not been such a disaster.
Caesar’s command as proconsul in 59 BC was at first limited to Italian Gaul1 and Illyricum. It was then extended to Gaul beyond the Alps. There was good reason for posting Roman forces in this area. German and Gallic tribes were once more on the move and Roman memories of the Cimbric War were only half a century old. The Helvetian Gauls had, at the time of Caesar’s proconsulate, already been forced southwards into north Switzerland by pressure from the Germanic Suebi. When the Suebi, intervening in Gallic tribal disputes, infiltrated west of the Rhine, the Helvetii, now in danger of being isolated from the rest of Gaul, decided to migrate westwards, and asked in 58 BC permission to move peacefully through the Roman Province (southern France). Caesar, as he explains, unable to see where such a movement might end and remembering that the Helvetii, in alliance with the Cimbri, had once inflicted humiliating defeat on a Roman army, refused his permission and built an elaborate 19-mile2 (28km) earthwork, complete with forts and command posts, between Lake Geneva and the Jura mountains, to block the migrants’ southward exodus. The extent of this fortification and the speed with which it was constructed are further testimony to the growing part played by military engineering in Roman strategy during this period of their history.
Caesar had already gained time by a rather disingenuous protraction of negotiations with the Gauls, and he was able to collect five legions in north Italy before the Helvetii, frustrated by his Geneva line of fortifications, had made their way with difficulty across the Jura mountains and the valley of the Saône. He attacked the Helvetii and inflicted a defeat on the clan that formed their rearguard as it waited to follow the main body across the Arar river (Saône). Very swiftly bridging the river, Caesar followed in their tracks for some two weeks until, encouraged by difficulties which he had with his corn supply, they unwisely took the offensive. After a battle which lasted into the night, the Helvetii were defeated. As a result, other tribes, fearing reprisals from Caesar, refused to supply them with corn. Starvation forced them to surrender, and Caesar resettled them in their Swiss homeland. If his ambition had been less far-sighted, it would have been simple and lucrative to sell them all as slaves. But the Helvetii, apart from their inconvenience elsewhere, were required in their original location – as a buffer state against the Germans.
This move, of course, made no sense unless the German infiltration into Gaul were at the same time halted. After an uncompromising diplomatic exchange with Ariovistus, king of the Suebi, Caesar found himself committed to a new war – which indeed he must have expected. The generation of Roman soldiers which Caesar commanded – if one discounts experience gained against Spartacus’ German followers – had not previously encountered German warriors, and the new enemy’s towering physique and warlike reputation dismayed them. At one point something like a panic occurred. But Caesar’s charismatic leadership and the fearlessness which he communicated especially to the Tenth Legion, his corps d’élite, soon rallied officers and men alike. His truculent oratory, capable of kindling mobs, could also inspire an army. The Romans defeated Ariovistus in a major battle in the plain of Alsace and drove him back across the Rhine – which he never recrossed. In this action, Publius Crassus, who was to meet so untimely a death at Carrhae six years later, was in charge of Caesar’s cavalry, and at a difficult moment his initiative swung the Roman reserve line into action on the hard-pressed left wing, turning a doubtful issue into a certain victory.
■ Caesar and the Belgic Gauls
After the victory over Ariovistus, Caesar travelled south to perform his judicial functions as governor in Italian Gaul. Meanwhile, he left his army, under command of a deputy, encamped for the winter west of the Jura mountains. But the Belgic Gauls to the north, who were of mixed Celtic and Germanic extraction, were preparing for war.
In the following summer, after arranging for some diversionary operations by the Aedui, a friendly Gallic tribe, Caesar met a combined force of Belgic tribes, some 40,000 strong, in a battle on the Axona river (Aisne). Caesar’s camp had been fortified on a low hill, with the bend of the river embracing it. The corn supply was again in question and the position was chosen not only for tactical defence but to prevent an enemy encircling movement which might cut the Romans off from friendly country in their rear – the source of their provisions. Anticipating battle on level ground in front of the camp and being heavily outnumbered, Caesar protected his flanks on either side by digging trenches; these extended from the Roman camp at one end to terminal forts in which artillery engines were installed. A battlefield was thus prepared, as in a kind of arena.
However, despite skirmishing in which Caesar’s cavalry had the advantage, neither army would risk attacking across the intervening marsh. The Belgians then found fords on the river, and attempted to cross in order to cut Roman communications in the rear. This plan was defeated by Caesar’s prompt use of cavalry and light-armed troops, which, attacking the enemy in the water, inflicted heavy losses. The Belgians had already, in the course of their march, failed to capture a Gallic town to which, as an ally, Caesar had sent timely aid; now, finding themselves short of provisions, they became disheartened. It was decided that the tribes should disperse, each to its own territory, on the understanding that all should reassemble for the defence of any one that was attacked. Their retreat, however, was so disorderly and unplanned that the Romans were able to fall upon the various contingents separately and massacre them amid scenes of confusion.
Most of the Belgic tribes were now glad to make peace with Caesar, but the strongest of them, the Nervii, still defied him. Having gained intelligence of the normal Roman order of march, they decided on a surprise attack. Mainly an infantry force, they issued from a wooded hilltop, driving Caesar’s cavalry vanguard before them, then swept across the Sabis river (Sambre) and uphill, to attack the Romans as they made ready to entrench their camp. Six Roman legions had marched in front of the baggage, which was guarded by two rear legions. This differed from the arrangement which the Nervii had been led to expect, for when there was no immediate likelihood of fighting, each legion was separated by its baggage from the next.
Even then, the surprise was so effective that the Romans scarcely found time to put on their helmets and remove the covers from their shields. Snatching a shield from one of his rear men, Caesar made his way to the front line, rallying his troops in person in the thick of the fight. The Romans suffered serious casualties, but were saved from disaster largely by their training and by the fact that officers and men knew what to do without being told. The Nervii, who had relied on surprise and superior numbers, found themselves fighting at a disadvantage when the Roman rear legions arrived. Many of them fell in battle, resisting with desperate courage, but the Romans now had control of the situation; on that day the Nervii were utterly destroyed as a fighting force.
Caesar completed his conquest of Belgic Gaul in a brief campaign against the Aduatuci, a Germanic tribe which had been associated with the Cimbri. They had set out to help the Nervii but, too late for the battle, found themselves isolated. Caesar demanded the surrender of their weapons, but some were secretly retained, and the Aduatuci attempted an armed sally from their town by night. For this kind of action Caesar was prepared with signal fires. He inflicted heavy losses in the fighting which followed, and sold the surviving population – 350,000 persons – as slaves.
■ Tidal Seas
Publius Crassus, in the same campaigning season, had been sent to force the submission of the Gallic states on the Atlantic seaboard. This submission was soon received, and it should be noted that Caesar now regarded as suspect any tribe which did not approach him with offers of peace. In the following year, however, the Veneti (of the south Brittany region) led neighbouring tribes in a resistance movement and seized Roman officers who had been sent on forage missions among them, the object being to force the release of hostages whom they themselves had previously given. Indignant at this act of treachery, Caesar prepared for war against the maritime Gauls. This demanded the use of a navy. At the mouth of the Liger river (Loire) he built ships, recruited rowers from the Province (southern France) and engaged sailors and pilots.
The south Brittany coast is indented by a series of estuaries, which, even today, impedes motor traffic. The Veneti and their neighbours built their strongholds on coastal eminences, which were islands when the tide flowed and peninsulas when it ebbed. Any land attacks on these citadels would be frustrated by the incoming tide, whereas a naval force would be left on the rocks when the water receded. The Romans, with great effort, built moles and raised siegeworks to provide themselves with a base of operations. But when the defenders were seriously threatened, their navy always arrived and evacuated them, together with their possessions, and the Romans were obliged to repeat the same engineering feat elsewhere.
The destruction of the enemy’s fleet thus offered the only solution. But here again the Romans were at a disadvantage. The Gallic ships were built of oak, with massive transoms fixed by iron nails of a thumb’s thickness, and they relied on stout leather sails. These ships were intended to resist the Atlantic wind and waves, and they also resisted the rams of the Roman war galleys. Their greater height made them difficult to grapple and thus invulnerable to boarding parties. The Gauls again were at an advantage when missiles were exchanged at sea, launching their weapons from a higher platform. Even when the Romans mounted turrets on their decks, it did not raise them above the enemy’s lofty poops. Moreover, the Gallic ships had flatter bottoms and were in less danger of being stranded in the shoals, while their navigators had intimate knowledge of the coast and the tides.
However, with perseverence, ingenuity and good luck, the Romans, under command of Decimus Brutus (who was destined later to be one of Caesar’s assassins), were at last victorious in a decisive sea battle. With sickle-like hooks fitted on long poles, they attacked the enemy’s rigging and tore away his halyards. With the consequent collapse of their yards and sails, the Gauls were powerless, for their ships did not make use of oars. It was thus possible for two or three Roman galleys to attack a single Gaul and destroy the enemy fleet in detail. It also happened that the wind dropped, and fleeing Gallic ships were becalmed and overtaken. Once the fleet of the maritime Gauls had been thus eliminated, Caesar had no difficulty in subduing the states of the Atlantic coast, which had depended completely on their ships. He was quite merciless, for he considered that the arrest of his officers, after a negotiated submission, was a breach of international law. All the leading men of the Veneti were executed and the rest sold as slaves.
■ Operations in Germany and Britain
Caesar’s campaigns in Gaul had begun as a defensive operation designed to keep the Germans out of Gaul. If the Romans did not intervene in Gallic tribal disputes, taking full advantage of Gallic political instability, then the Germans were certainly willing and able to do so and, after the experience of the Cimbri and the Teutones, western Europe dominated by land-hungry German invaders was a prospect which no Roman could regard with equanimity. The continued success of Caesar and his officers in various parts of Gaul was consequently greeted by periods of recurrent public thanksgiving in the city.
In the north and west of Gaul, however, Roman action was no longer purely defensive. It becomes clear from the tone of Caesar’s commentaries that he regarded himself and his army as the agents of a civilizing mission. He also intended that the Gallic habit of tribal warfare should give way to widespread Roman law and order, and that the whole country as far as the Rhine to the east and the Channel to the north should be accessible to Roman trade, enterprise and public works. His desire to ensure that these frontiers should remain inviolate led, in 55 BC, to campaigns (northward and eastward) against the peoples who inhabited the lands beyond them.
In this year, German tribes, already threatening the Meuse region, crossed the Rhine under pressure from the Suebi. Caesar negotiated with the migrants, but realized that they were only playing for time. He eventually took them by surprise and defeated them with great slaughter. He then, in ten days, built a wooden bridge over the Rhine and marched his legions across, for a reconnaissance in force which lasted 18 days. He did not attempt a battle with the Suebi but retired again into Gaul, destroying his bridge, having frightened his enemies and put heart into his allies.
It was already late summer in the same year when Caesar set on foot an expedition to Britain. British help to his Gallic enemies provided a military pretext, but his motives, personal ambition apart, were partly those of an explorer. He sent his trusted officer Gaius Volusenus to carry out coastal reconnaissance, and he dispatched Commius, a friendly Gallic chief, to negotiate on amicable terms, if possible, with the natives. Some British tribes had already sent conciliatory embassies to Caesar in Gaul.
When preparations were completed, Caesar sailed with two legions in 80 transport vessels, escorted by warships, across the Channel (probably from a point near Boulogne). The British were assembled on the cliffs when he arrived, but the cliffs alone made landing impossible until he found an open beach seven miles farther up-Channel (probably between Walmer and Deal). Here the Roman legionaries landed under great difficulties, wading through water with full packs while British cavalry, chariots and infantry attacked them. Fortunately, it was discovered that the Britons had never seen oared galleys and were frightened by the Roman warships. The movement of the oars possibly suggested the legs of a sea monster. Caesar also used the warships’ dinghies, together with light reconnaissance craft, to aid his men as they struggled in the surf. Landing was eventually effected and the Britons were driven back. But the Roman cavalry, embarked in a separate transport fleet, had been forced by foul weather to return to the Continent, and without them Caesar’s characteristically swift pursuit of a conquered enemy was made impossible.
The Romans at once fortified a camp. Caesar received a chastened embassy from the conquered Britons, and Commius, who had been held in chains, was now released. But the spring tide unexpectedly filled the beached Roman galleys with water and heavy storm damage rendered the whole fleet unseaworthy. In these circumstances, the Britons immediately took heart and renewed hostilities. However, with foresight Caesar had laid in corn supplies, and he now repaired his less seriously damaged ships with wood and bronze material which he salvaged from the 12 total wrecks. He again imposed himself on the Britons and was promised that hostages would be sent to him in Gaul. He then recrossed the Channel before the autumn equinox. Only two tribes complied by sending hostages.
In the following year, despite turbulence among the Gauls, Caesar made an expedition with five legions, 2,000 horses and a correspondingly larger fleet, to his previous point of landing in Britain. On this occasion he penetrated inland, forded the Thames, and subdued the British king Cassivellaunus, who ruled over the Hertford area. Caesar again returned to the Continent before winter, having once more been obliged to repair a fleet damaged by storms. The two expeditions to Britain amounted to extended raids rather than invasions. It is surprising that no British ships attempted to interfere with the Roman landing on either occasion. No doubt they would have been heavily outnumbered. Perhaps the Britons had lost ships helping the Veneti, or perhaps they were warned by the example of that unhappy people.
Another point of interest is the British use of chariots. These were not employed in warfare by the Gauls of Caesar’s time. In Britain, by contrast, Caesar writes respectfully of their military value. The charioteers could manoeuvre with great skill and drive down steep slopes without losing control. In the early stages of a battle, the chariots were driven among the enemy cavalry to create confusion. Missiles were thrown from them, the chariot crews being able to balance themselves, if necessary, in a kind of tight-rope act, on the poles that supported the horses’ yokes. The noise of the wheels was daunting, though there is no mention of scythe attachments. At a later stage in the battle, chariot-borne warriors dismounted and fought on foot, while drivers waited at a distance, ready to pick them up and drive them from the battlefield at speed if circumstances thus dictated. One is reminded of Homeric accounts of chariot warfare.
■ Caesar against Vercingetorix
Caesar’s initial conquest of Gaul had been deceptively simple. The Gauls did not remain docile, and Gallic uprisings alternating with Roman reprisals soon assumed the aspect of a vicious circle. Not long after Caesar’s British campaign, the Belgic tribes revolted. Two of Caesar’s senior officers were lured out of their camp and killed with almost their entire force, while another Roman camp was relieved by Caesar’s arrival in the nick of time. The Germans once more intervened and a new retaliatory expedition across the Rhine became necessary. Caesar built a bridge even more quickly than he had done on the previous occasion. But when he had subdued the Gauls in the north-east, he had one of their leaders flogged to death. The resentment and apprehension which this caused was a stimulus to further revolt.
During the period of the Gallic Wars, Caesar spent every winter in north Italy where, apart from all other considerations, he was able to keep in touch with Roman politics. Returning to Transalpine Gaul in 52 BC, he found the whole country in a state bordering on general rebellion. At Cenabum (Orleans), a massacre of the Roman trading community had taken place. The situation was so dangerous that when Caesar reached the Roman Province in southern France, he dared not summon his legions to him from their stations farther north, lest they should be attacked while he was not present to command them in person. Nor dared he travel through Gallic territory unattended by his army.
However, he gathered some troops in the Province, marched up into the Cevennes amid winter snows, and then left his force to occupy the enemy’s attention, while he himself travelled so swiftly north-eastwards, through once friendly areas, that his old Gallic allies had no time to organize treachery, even if they would have wished it. Thus rejoining his legions, Caesar captured several rebel strongholds and avenged the massacre at Cenabum, but he now faced an enemy leader of great courage and skill in the person of Vercingetorix, chief of the Arverni tribe in central Gaul. At the siege of Avaricum (Bourges), both Romans and Gauls suffered intense hardship, for Vercingetorix’ scorched-earth strategy inflicted terrible privations on enemies and friends alike. Meanwhile, the Gauls had learnt to counter Roman siege techniques. The defenders set fire to Caesar’s assault towers and undermined the ramp which he had raised against their walls; many Gauls were by occupation iron-miners. But the Romans took Avaricum at last. Caesar says that only 800 out of 40,000 persons escaped to join Vercingetorix in his impregnable camp amid the marshes. Vercingetorix now retreated to another impregnable position, this time deploying the tribes under his command on a mountainous plateau before the town of Gergovia in Arverni territory. Caesar managed to occupy a hilly eminence opposite the town and established here a small garrison, which he connected with the main camp by means of a double ditch and rampart. The result was to impede the enemy’s supplies of food and water, but the move was not decisive, and while Caesar faced Vercingetorix at Gergovia he was not available for operations elsewhere. Once, when his departure was temporarily necessary to deal with a threatened revolt among the Aedui, the enemy launched a sortie against the force which he had left behind him and the Roman camp was defended only with difficulty.
In these operations, Vercingetorix used archers and other missile-troops in great numbers and with devastating effect. The Romans retaliated vigorously with catapult artillery. Finally, a Roman assault on the fortified plateau miscarried, although it had been carefully planned by Caesar. Legionaries who broke through the defending wall and tried to push their attack into the town itself were repulsed with heavy loss. They had exceeded their orders and Caesar reproved the survivors, although he would no doubt have commended their initiative had they been successful. For the sake of prestige and morale, he now waited until his cavalry had gained some minor victories before evacuating his positions at Gergovia.
■ Operations at Alesia
The action at Gergovia amounted to the most serious reverse that Caesar faced in the whole of the Gallic Wars. He had for some time been contemplating withdrawal, to deal with threats elsewhere in Gaul. But the mere fact of his withdrawal encouraged revolt and led to the defection of the Aedui, whose old allegiance to him had been wavering as a result of Vercingetorix’ continued success. In the north, several tribes did not join the general rebellion, and Belgians who revolted were overcome by Caesar’s deputy, Labienus, on the Seine near Lutetia (Paris). Vercingetorix had now collected a vast force of cavalry and launched an offensive against the Gallic peoples on the frontiers of the Roman Province. Caesar, however, had enlisted the help of German cavalry from Rhine tribes with whom he had previously come to terms. Vercingetorix was repulsed and retired to Alesia in a territory subject to the Aedui (almost certainly at Alise-Sainte-Reine).
The Gallic leader hoped to repeat the experience of Gergovia, but he now saw that Caesar was bent on a massive blockade. Before the Roman circumvallations could close round him, he sent out his cavalry contingents each to its own tribe, to organize relief forces from every direction. Caesar had soon to deal with these relief forces. But his double circumvallation was so effective that he was able to hold off all attacks from outside and from within, until Vercingetorix and his force were starved into surrender. Vercingetorix was held captive for six years, for exhibition in Caesar’s triumph in Rome. He was executed, according to the usual custom, when the celebrations were over. Pompey would have behaved more chivalrously.
In Caesar’s commentaries, engineering operations around Alesia are described in great detail. The Roman entrenchments linked an encircling chain of camps and forts. The inner ditch was 20 feet (6m) wide, with sheer sides (i.e., not tapering at the bottom), and the main circumvallation was constructed 400 paces3 behind this ditch. Here, there were two trenches each 15 feet (4.4m) wide and 8 feet (2.4m) deep; the river was diverted to carry water into the inner trench wherever possible. Behind the trenches was a 12-foot (3.6m) earthwork and palisade, with antlered prongs projecting from it. Breastworks and battlements were overlooked by turrets at intervals of 80 feet (23.6m). Caesar also sowed the ground beyond his fortifications with prongs and pitfalls of various patterns, illustratively or humorously termed “lilies” and “stingers” (stimuli). A parallel line of fortifications was then provided as an outer circumvallation against the inevitable relief force. The inner perimeter was 11 Roman miles (10.1 miles/l6.3km) long; the outer 14 Roman miles (12.9 miles/20.7km).
Caesar writes that the Gallic relief force, when it came, amounted to 250,000 infantry and 8,000 cavalry. Belgic troops were rallied by Commius, Caesar’s old friend, who now preferred liberty to civilization and had at last taken sides with Vercingetorix. Meanwhile, the noncombatant population of Alesia had been driven out by the Gallic garrison – perhaps a preferable alternative to the slaughter and cannibalism that had been proposed. The wretched outcasts begged to be accepted as Roman slaves and fed as such. But Caesar, who had laid in military provisions only for 30 days, forbade them to be fed.
When the Romans were attacked simultaneously by the huge relief force and the desperate men from Alesia, the issue remained for some time uncertain, but Caesar had apparently held his German cavalry in reserve and his use of it late in the day routed the enemy cavalry and exposed to massacre the archers and light-armed troops who had accompanied them.
The besieged garrison now made a night attack on the Roman positions. The Gauls had become more sophisticated in their methods of siege warfare, and were armed with ladders and grappling hooks. Many missiles were exchanged in the darkness, and Caesar seems to imply that casualties were caused on both sides accidentally by what had been intended as “covering fire”. Meanwhile, Roman legionaries had taken up their stations on pre-arranged plans and the Gallic sortie was contained and repulsed.
The final assault on the Roman circumvallation, which was made simultaneously from within and without, was again decided by cavalry action. Caesar had unostentatiously sent out a cavalry force, which took the outer enemy in the rear, just at the moment when they were heavily engaged on the ramparts. At this moment, in particular, the situation at Alesia must have been that of a nest of boxes. In the centre was the town. Vercingetorix had fortified the surrounding plateau with a six-foot (1.8m) wall, to protect his camps in the enclosure. Outside this was the Roman double circumvallation, now attacked by the Gallic relief forces from beyond. But these finally had been surprised by the appearance of Caesar’s cavalry behind their backs.
After this action, which forced the surrender of Alesia, many Gallic leaders fell into Caesar’s hands. But Commius, after further adventures, escaped to Britain, where he ruled over a migrant branch of his own Belgic tribe in what is now Hampshire.
■ Tactical Considerations
The organization and equipment of Caesar’s army in Gaul was virtually that which had been introduced by Marius. There was no question of manipular quincunx formation. The army ordinarily fought in three unbroken lines. In any one legion, four cohorts in front and three apiece in the rear ranks was normal distribution. Sometimes the legions themselves appear as tactical units, as for instance in the battle against the Nervii, where Caesar ordered his tribunes to close up the gap between the isolated Seventh Legion and the rest of the battle line, thus obviating the danger of encirclement. On occasion, a two-line battle formation might be adopted, as it was by Publius Crassus while fighting against the Gauls of Aquitania.
In his earlier Gallic campaigns particularly, Caesar seems to have made full use of hillside positions. This, however, was not an advantage if the enemy possessed a strong archer force which outranged the Roman heavy javelin. Publius Crassus, leading the ill-fated advance guard of his father’s army at Carrhae, discovered this to his cost. For on a sandy hill, the rear ranks were raised above the front ranks only to offer better targets to the Parthian bowmen.
The Roman javelin (pilum), as used by Caesar’s armies against the Gauls, embodied the Marian principle of buckling on impact. This effect was achieved not by a breakable wooden peg but by soft iron in the shank of the javelin, which bent and was hard to remove. In many instances, Gallic shields, which had evidently overlapped each other when their owners adopted a close formation, were pinned together by a single pilum. In such circumstances, the Gauls had abandoned their shields and fought unprotected. In the later battle against the Nervii, however, we hear of pila being intercepted and launched on a return journey. Perhaps these were javelins which fell flat to the ground, without head-on impact. Perhaps, also, the bending of the iron was produced not so much by the impact as the attempted withdrawal. In any case, the “interception” of javelins can hardly have involved catching them as they hurtled through the air!
The adoption of a three-line or two-line formation must have been determined largely by topographical considerations. In Caesar’s battle against the Belgic confederacy, the plain on which he planned to fight yielded a battle front co-extensive with the adjacent wall of his camp. However, in warfare against consistently superior forces, there was an ever-present danger of encirclement, and apart from the normal use of cavalry on the wings, Caesar made tactical use of fortifications. In the battle against the Belgic confederates, he protected his flanks with an earthwork on either side. Tactical fortifications were indeed a conspicuous feature of Roman warfare in the first century BC. Caesar was able to develop their use on account of the astounding speed and efficiency with which his technical arm did its work. We may compare his building of bridges and fleets.
Caesar relied on a skilled corps of artificers for specialist work. But the legionaries were still responsible for digging trenches and raising the earthworks round camps. However, though dolabrae were carried, the Roman soldiers, operating usually in enemy country, often travelled light, leaving their equipment to be transported by large mule trains located at intervals between the marching legions. The legionaries were thus ready to resist a sudden attack, and to provide against such a contingency, they sometimes marched in four parallel columns (quadratum agmen), which could abruptly turn and face towards either side in the form of a battle line. When surrounded, the Romans might also adopt the formation of a ring (orbis) – an ancient counterpart of the nineteenth century British square.
When Caesar assumed command in Transalpine Gaul, there had been only one legion stationed there. Caesar finished the Gallic Wars with ten legions under his command, but these were not up to the strength of those which Marius had levied (5,000 men). A legion of Caesar’s army was not usually more than 3,500 strong. It will be realized from this how enormously the Romans were outnumbered in the course of the Gallic Wars. Caesar himself says that the siege of Alesia could not have been undertaken without recourse to his elaborate fortifications. Without the aid of ramparts and ditches, towers and pits, he had not sufficient troops to surround the Gallic positions.
The Roman was traditionally a foot-soldier. However, cavalry was essential to Caesar, not only for flank protection, but for swift pursuit of a defeated enemy. Such speed in pursuit was, in fact, characteristic of his generalship and goes far to accounting for the decisiveness of his victories. Since Marius’ time, the Romans had regularly used foreign (non-Italian) cavalry. Caesar’s horsemen were mainly drawn from Spanish and Gallic allies. Similarly, he used Cretan and Numidian archers and Balearic slingers. But against Vercingetorix he also made great use of Germans from the tribes which he had conciliated beyond the Rhine. It was not simply that Gauls in this campaign were less available or less trustworthy. German horsemen were hardy riders, who despised the use of saddlecloths. Their horses were physically inferior to Gallic mounts but were very highly trained. German cavalry fought in conjunction with infantry, operating in couples, each composed of a horseman and a footman, associated in a kind of knight-and-squire relationship. If necessary, the footmen could support themselves in fast moves over long distances by hanging on to the horses’ manes4. Caesar himself noticed the advantage of combining infantry with cavalry; one of the assets of the British war chariot was that it combined the mobility of horsemen with the stability of foot soldiers. Again, typically Roman in his respect for military traditions, Caesar did not attempt to impose foreign methods of fighting on his own men, but employed foreign troops which operated according to their own traditional methods, while making good Roman deficiencies.
In this context, it should also be noted that Caesar recruited a legion of Gallic infantry, who later received Roman citizenship. Their purpose was to replace two Roman legions which, on orders from the Senate, he had sent back to Pompey in 51 BC – for use in a Parthian campaign which never materialized. The Gallic legion was known as the Alaudae (“Skylarks”). The reference was perhaps to their helmet crests, and the nickname may have been one which the Gallic legionaries conferred on themselves, for alauda (cf., French alouette) is a word of Gallic, not Latin, extraction.
■ Caesar against Pompey
The fall of Alesia did not automatically bring Gallic resistance to an end, but it deprived the Gauls of unifying and coordinating leadership. During the following year (51 BC) Roman armies were able to deal with their opponents piecemeal as they had done before the emergence of Vercingetorix, and as Caesar’s term of office and command approached its end, he could justly claim to have conquered and subdued the rebellious warriors of Gaul.
In a political situation delicately balanced amid a variety of competing interests, Caesar’s enemies at Rome, who possessed what amounted to a casting vote, managed to face him with a clearcut option which admitted of no compromise. Either he must disband his army and return to Rome as a private person, without so much as a bodyguard, or else he must descend upon Rome at the head of an invading army, as the enemy of the Republic. The former alternative meant suicide in a political, and perhaps even a more literal, sense. In 49 BC, Caesar, with his army, crossed the Rubicon river (between Ravenna and Rimini) which divided Italian Gaul from Roman Italy. Pompey had with some hesitation placed his loyalty to the constitution before his old alliance with Caesar. He, also, could now have exclaimed, “The die is cast!” For both men had been called upon to make difficualt decisions. Lucius Domitius Ahenobarbus, appointed as Caesar’s provincial successor, refused to be advised by Pompey and tried to resist Caesar at Corfinium (near Corfinio). Caesar captured him, released him and took command of his troops. No Sullan or Marian massacre ensued at Rome, but Caesar tried unsuccessfully to prevent Pompey from embarking his army at Brundisium, whence it was skilfully piloted, from among the Caesarian entrenchments and moles, across the Adriatic, to form the nucleus of a new base in Greece. The rulers and governors of the East owed their positions to Pompey’s goodwill, and he could rely on them for financial and military support.
Caesar lacked a fleet and could not therefore immediately follow Pompey. Instead, he turned his attention to Spain, the provincial territory which Pompey had governed from Rome through his legati. Marching through the south of France, Caesar found the Massilians hesitant and, while he negotiated with them, Domitius Ahenobarbus – abusing the clemency shown him at Corfinium – arrived with a few merchant ships and rallied local support for Pompey. Caesar built 12 ships at Arelate (Arles), in the Rhône delta, and left them with Decimus Brutus – victor over the Veneti – for the purpose of blockading Massilia (Marseille). From the cutting of the timber to the launching of the ships, the work took only 30 days. The wood was, of course, unseasoned, but Roman fleets were often built quickly and ad hoc, and they were not required to last. Other forces were also left to besiege the Massilians by land.
Fighting in Spain centred on Ilerda (Lérida) on the Sicoris (Segre) river, a tributary of the Ebro. The Pompeians, accustomed to guerrilla tactics like those used in Spain by Sertorius, fought in a flexible and loosely organized way, which at first disconcerted Caesar’s troops. The corn supply was once more of crucial importance, as always where, in consequence of latitude or altitude, crops ripened late in the season. Lucullus had had the same trouble in the Armenian mountains. Caesar’s supplies were cut off when the river, abnormally swollen by melting spring snows, swept away his bridges. At a later stage, he crossed the river in boats of hide stretched on light wooden frames, which were conveyed to the water on trailer-linked wagons. Caesar says that his British experience had taught him so to construct boats.
At last, Pompey’s legati, Afranius and Petreius, were themselves cut off from supplies and forced to capitulate. After much fighting, Massilia (Marseille) also surrendered. Caesar returned to Italy, ready for an offensive against Pompey himself. Despite the Pompeian fleet, which had been detailed to prevent his crossing into Greece, Caesar managed to transport his troops unexpectedly in winter across the Adriatic. A further contingent, left behind with Marcus Antonius (Mark Antony) for lack of ships, crossed the Adriatic without further difficulties later in the winter.
The armies of Caesar and Pompey confronted each other at Dyrrhachium (Durazzo). Caesar’s force was the smaller, perhaps three-quarters the size of Pompey’s, but it was the better army. Pompey realized this and wisely avoided a pitched battle, choosing instead to fortify an enclave on the Adriatic coast, 15 Roman miles (13.8 miles, 22.2 km) in perimeter. Caesar characteristically enclosed this enclave with his own outer circumvallation.
■ The Supreme Victor
Military history in general tends to familiarize us with battles which are decided on a fateful day and battlefields which are reminiscent of playing fields. By contrast, Caesar’s mode of fighting, with its reliance on earthworks and ditches, anticipates protracted twentieth-century struggles amid extensively prepared positions. At Dyrrhachium, Pompey’s determination not to be drawn into a pitched battle was in every way wise. He had access to sea-borne supplies and reinforcements, while Caesar, without a navy, was cut off from Italy. The besiegers grew hungrier than the besieged, but lacking corn they resorted to digging up a local root which could be mixed with milk and made edible.
Eventually, Pompey, who had been growing ever stronger, broke through Caesar’s lines at a weak point near the sea. Caesar’s counter-attack on one of Pompey’s camps proved very costly and almost disastrous. The Caesarian cohorts, approaching the camp – which had been much ramified and extended – lost their way and mistook an entrenchment which connected the camp with the neighbouring river for part of the camp itself. Demolishing the rampart in order to make their way through, they were taken at a disadvantage by a Pompeian force, with resulting confusion and panic in which nearly 1,000 were killed. If Pompey had exploited his opportunity as they fled, he might have finished the war on that day.
Caesar’s strategy at Dyrrhachium thus ended in fiasco, and he marched away into Thessaly, perhaps threatening Thessalonica or perhaps mainly in search of corn. If he hoped at the same time that Pompey would be encouraged to take the offensive, then his optimism was eventually justified. Pompey was persuaded by his influential and aristocratic officers to offer battle. He did so reluctantly, but should not be accused of weak-mindedness. His advisers were highly placed men who could easily have swayed the sympathies of the legions under his command. At Pharsalus, Caesar reserved eight cohorts for attack on the enemy’s larger but inexperienced cavalry force. These cohorts advanced irresistibly, thrusting with their javelins at the faces of the young horsemen. Once the cavalry had been routed, the Pompeian legions were unable to withstand the impact of Caesar’s third line, now thrown fresh into the battle. Pompey escaped and made his way to Egypt, where he was murdered on arrival by orders of the ruling Ptolemy, who dared not offer hospitality to a loser.
On arrival in Alexandria, Caesar obliged Ptolemy to accept Cleopatra (his sister and wife, according to Ptolemaic precedent) as joint ruler of Egypt. However, hostilities soon followed, as a result of which Ptolemy XIII was drowned in the Nile and his brother Ptolemy XIV placed on the throne as a mate for Cleopatra, only to be murdered by her orders. Caesar himself had already obtained Cleopatra as a mistress; she had a son Caesarion (“Little Caesar”) after the conqueror’s departure from Egypt.
Meanwhile, Pharnaces, the son of Mithridates, had taken advantage of Roman civil strife to attempt the reconstruction of his father’s empire. Caesar, avenging an unsuccessful deputy, defeated the ambitious ruler at Zela in Pontus, and immortalized the event with his laconism “ Veni, vidi, vici” (I came, saw and conquered).
After brief political activity in Italy, Caesar crossed into North Africa to deal with surviving Pompeians, some of whom had, more than two years earlier, with Numidian help, defeated his officer Curio. The battle of Thapsus (46 BC) was here decisive. After Caesar’s victory, Cato, left with the hopeless task of defending Utica, philosophically committed suicide. Petreius and the Numidian king Juba made a suicide pact, involving an after-dinner duel to the death. Metellus Scipio, who had commanded at Thapsus, successfully stabbed himself. Afranius was captured; Caesar, whose clemency did not usually extend to second-offenders, had him executed. Domitius Ahenobarbus had already been killed at Pharsalus.
In the west, however, Caesar’s enemies rallied. His old second-in-command in Gaul, Titus Labienus, had defected to Pompey. A survivor of the Greek and African campaigns, Labienus now aided the sons of Pompey in a desperate battle at Munda in southern Spain. Nobody had a better insight into Caesar’s mind and methods than Labienus. But it was a case in which enemies understood each other better than allies. A tactical move by Labienus was misinterpreted as flight. Flight resulted, and Labienus was killed. Of the two Pompey brothers, Gnaeus was overtaken and killed, but Sextus lived to fight another day. Caesar, before his assassination in 44 BC, was planning new eastern conquests, but he could hardly have undertaken them before settling the outstanding account in Spain. With Sextus Pompeius at large, the victory at Munda remained incomplete.
REFERENCES
1 The Romans called the Gallic regions of north Italy Cisalpine Gaul (Gallia Cisalpina), i.e. near-side Gaul. North of the Alps lay Transalpine Gaul (Gallia Transalpina).
2 Roman miles.
3 1 pace (passus) = 5 Roman feet
1 Roman foot = 11.65 inches (296mm)
400 paces = 1,942 English feet (9592m)
The above measurements are in Roman feet, as given by Caesar.
4 A mixed unit of cavalry and infantry (cohors equitata), modelled on German practice, later formed a regular part of the Roman auxiliary forces.