Caesar's Gallic Wars (58 – 50 BC) : Opposing Forces

The Roman army that campaigned in Gaul in the 1st century BC was to all intents and purposes a professional one, with many soldiers in the legions regarding their military service as a career. The soldiers were equipped, trained and paid by the state, often serving for many years at a stretch. The Gallic armies were completely different. Gallic warfare was based on the values of a warrior society; while the elite warriors may have been able to spend time raiding neighboring tribes and may have possessed high quality arms and armor, tribes were unable to maintain armies for long because of the lack of any organized supply system and the need for many of those fighting to return to their fields. The Roman conquest of Gaul was a clash between two cultures employing very different methods of waging war.

The Romans

The Roman was made up of two types of of troops: the legions, comprising Roman citizens and auxiliaries, and non-Romans who fought alongside Roman generals because of treaty obligations or out of choice. When Caesar started his governorship he had four legions assigned to his command, but he immediately began recruiting more, mainly from northern Italy, and possibly not being too strict about the citizen status of his recruits, since much of the population of Cisalpine Gaul did not have full Roman citizenship.

In the Imperial period a legion was usually commanded by a legate who was a senator or equestrian, but in the late Republic the legion had no permanent commander. Instead, the provincial governor appointed senators from his staff to command one or more legions. These might he legates of quite senior status (Caesar's most experienced legate, Labienus, had held the important magistracy of Praetor), or they might be much younger men like Publius Crassus who was just beginning his senatorial career. Each legion had six military tribunes who were usually equestrians or the sons of senators gaining military experience before starting their own political careers. The most important officers within the legion were the centurions, and there were 60 in each legion. Appointed for their bravery and experience, these men were responsible for the training of their centuries and the day-to-day running of the legion whether on campaign or in winter quarters. The senior centurions of each legion (the primi ordines) regularly attended Caesar's councils of war and would have contributed to strategic discussions; they were the backbone of the legion.

Legionaries were uniformed at state expense, and were well equipped for their military roles. Each legionary, with his mail coat and bronze or iron helmet, was armed as well as the most wealthy and successful Celtic warriors and this must have given them a huge psychological advantage when facing the Gauls. The large shield or scutum provided additional protection. The legionary's principal weapons were the pilum (javelin) and short sword, the gladius.

Recruitment to the legions was based on a mixture of conscription and volunteering, the only qualification for service being Citizenship, at least in theory. Recruits were supposed to be at least 17, although the majority were in their early 20s when they joined up. Roman ideology preferred recruits from rural backgrounds rather than from towns and cities with their softening and corrupting influences, but Caesar probably experienced little difficulty in raising troops for his campaigns in Gaul because there had previously been little wide-scale recruitment in Cisalpine Gaul. The legionaries signed up for military service of no fixed length, although they could expect to be discharged with a grant of land on which to settle after five years or so continuous service. Military pay was not especially good, but there were plenty of opportunities for enrichment, particularly on a lucrative campaign like Caesar's conquest of Gaul with the likelihood of generous amounts of booty.

While the legions were armed and equipped uniformly, and were principally heavy infantry, the variation in type of forces a successful army needed was provided by “auxiliary” units raised from other provinces of the Roman empire or from neighbouring states and tribes friendly to Rome. It was up to the provincial governor to maintain friendly relationships established by his predecessors with local tribes, such as the treaty of friendship between Rome and the Aedui. Caesar was so successful in his early campaigns in Gaul and his military prestige so great that he was able to attract auxiliary units from the Germans as well as support from Gallic tribes, who provided him with another source of cavalry that was particularly valuable when the loyalty of the Aedui wavered in 52 BC. Auxiliaries used their own fighting techniques, they were not trained in the Roman style of fighting, and were commanded by their own officers, usually members of the ruling elite of the tribe or state from which they were recruited.

Auxiliaries provided the Roman army's main cavalry force. The cavalry Caesar employed in Gaul, consisting mainly of Gallic or Germanic elites, was not always reliable or effective, and sometimes they lacked discipline, particularly early on in the campaigns. Its drubbing by the Nervian cavalry in 57 BC was probably the most serious setback it suffered, and by the end of the campaigns the cavalry was a powerful force that contributed to Caesar's victory in the Civil War. The German cavalry sometimes worked in concert with light infantry which allowed the holding of terrain in addition to the useful mobility of cavalry.

The Celtic-style saddle allowed Caesar's cavalry to be as effective as later stirruped cavalry, despite the absence of stirrups. Cavalry troops might vary considerably in their equipment, since they equipped themselves, hut a wealthy cavalryman might have a mail shirt and helmet, an oval or hexagonal shield which was more manoeuvrable on horseback than a rectangular one, a spear and a long sword, which was ideal for running down those fleeing from battle, one of the principal roles of the cavalry.

The Roman army in Gaul included slingers from the Balearics and archers from Crete and Numidia who provided lightly armed mobile troops to increase the firepower of the army, particularly at a distance or in a siege. Their role is rarely commented upon, but they added an important degree of flexibility to the Roman army. Additional infantry was provided by Gallic tribes in the same way as cavalry, and would have consisted of groups of warriors from tribes who were allied to Rome like the Aedui or Remi who surrendered to Caesar following his invasion. The wealthiest of these warriors were probably armed and equipped in a way very similar to the Roman legionaries, but the Gauls placed greater emphasis on individual prowess and prominent displays of courage in battle, rather than the discipline and training of the legions.

Logistical support was generally well organised, with a supply system usually reliant on shuttling provisions from a supply base to the campaigning army. The army made use of Gaul's navigable rivers to move supplies around, but the poor road system and the speed of Caesar's movements led to difficulties. Although Caesar could call on his Gallic allies and later the subjected tribes for supplies, his movements and the direction of the campaign were often heavily influenced by logistical demands. An understanding of this lay behind the Gallic scorched-earth policy in the revolt of 52 BC. When the legions were in winter quarters, Caesar ensured they were garrisoned in the territories of recently conquered tribes to serve the dual purpose of ensuring a strong military presence in newly reduced territory, and punishing those who resisted Rome by forcing them to feed the occupying army, a penalty that could have affected a tribe's ability to support its own population. The winter allowed troops time to recover from the often exhaustive campaigning that Caesar demanded of his armies, in particular those who were sick or had been wounded in fighting. Roman imperial armies had medics attached to them, and this may have been the case in the late Republic, too. In the aftermath of pitched battle Roman armies usually paused, sometimes for several days, so the dead could be buried and the wounded treated. The wounded would later be escorted to a base, probably a supply base, to recuperate before rejoining their units.

Gauls, Britons and Germans

In the 1st century BC Celtic tribes employed different methods of warfare. Although prowess in combat remained important for the tribal elite, in some tribes, particularly in southern and central Gaul, other means were becoming available to gain and maintain status. The Aeduan aristocrat Dumnorix fought as a cavalryman to display his elite warrior status, but he also held a monopoly over the wine trade, which enhanced his wealth and therefore his position within Celtic society. Encouraged by the impact of Mediterranean culture on Gallic society, the Romans interpreted this shift in emphasis as a demoralizing factor.  Caesar perceived the Belgae as the bravest of the Gauls 'because they are furthest away from the culture and civilization of Provence, and are least often visited by merchants importing degenerate luxury goods, and also because they are nearest to the Germans who live across the Rhine and with whom they are continuously at war'.
In most Gallic tribes, raiding neighbors was the warrior's principal means of acquiring wealth and position, and tribes sought to extend their influence over smaller neighbors. The bravest tribes, and therefore the most secure, were those with wide influence and many dependent tribes. Tribes might form alliances with neighbors or even, in the case of the Sequani, the Germans, in order to increase their own military prowess. Gallic war bands consisted of groups of warriors belonging to an elite class, following their chieftain and concentrating on raiding; larger-scale armies of the kind faced by the Romans in Gaul were probably less common, and may have included peasants, the dependent farmers who would not normally have been involved in regular warfare. If Caesar really did face an army of 50,000 Helvetii and their allies, it probably included tribesmen of all status, but we hear no details of them or how they were armed and equipped. The warriors equipped themselves according to their wealth and status: the braver and more successful, the more likely they were to be able to adorn themselves with beautifully decorated and high quality equipment.
Only the wealthiest warriors would have possessed mail coats, but such aristocrats could have been equipped in a way very similar to a Roman legionary, with the mail armor providing reasonably good protection from the slashing blows of the long Celtic swords, a bronze or iron helmet, sword and shield. Helmets, like mail coats, were probably very rare and worn only by the wealthiest warriors, but stylistically they were very similar to some Roman helmets; indeed the coolus  helmet which evolved into one of the main helmets of the Roman imperial army was originally a Gallic design. Gallic warriors carried spears and swords, the latter considerably longer than the Roman gladius. They were designed primarily for slashing rather than stabbing, and pointed to a fighting technique that required plenty of room for the individual to wield his long weapon. Though the Greek historian Polybius claims these long swords had a tendency to bend on impact, many were made of high quality iron and they were extremely effective weapons. The Gallic elongated rectangular shield was probably made of hide or wood like the Roman scutum. Some shields may not have been particularly thick or strong, which may explain why Caesar reports that the Roman pila were able to pierce several of them simultaneously; the bronze shields that survive from antiquity may have been for decorative or ceremonial purposes and not actually for use in battle. Given that the majority of warriors probably lacked body armor, and indeed some may have chosen to fight without armor to stress their courage and military prowess, the shield was a vital piece of protective equipment. When their shields were put out of action by the Roman pilla, the Helvetii became dangerously exposed to the Roman attack.
Celtic cavalry, manned by the wealthiest warriors, was particularly effective and scored significant victories against Caesar's more numerous auxiliary cavalry in the first couple of campaigning seasons. The lack of stirrups was no bar to powerful cavalry: the design of the Celtic saddle provided its rider with a secure mount from which to throw spears, thrust with a spear or slash with a sword and implement shock tactics. Some German cavalry may have used these saddles as well, but the horsemanship of the cavalrymen and their co-operation with the light infantry who regularly worked alongside the German cavalry was clearly impressive and indicative of at least some training, which we hear little about in any sources. The Celtic tribes in Britain were still using chariots, something that had gone out of fashion on the Continent, but their speed and agility caused the Roman infantry serious difficulties. The chariots served as battlefield 'taxis' for the wealthiest nobles, dropping them off at the fighting and then collecting them up again if they were injured or needed to withdraw from the battle.
Firepower was available in the form of slingers and archers, although these men were probably not members of the warrior class, as this form of warfare was not really regarded as 'heroic'. Slingers were sometimes involved in open warfare (such as the Gallic ambush of a Roman column in 54 BC), but more often in the defense of hill forts, along with archers. In preparation for the general revolt of 52 BC, Vercingetorix called up all the archers of Gaul; they were probably Gauls of the lower classes, but were vital to the success of the strategy of the revolt.
Very little is known about the organization of Gallic armies and their workings in pitched battle, although they seem to have relied heavily on the effectiveness of infantry and cavalry charges at the start of battle to break the enemy lines. Pitched battle, even at a small scale, provided one of the best opportunities to display military prowess and so was an important way of making war, but not all Gallic tribes were so keen on meeting the enemy in the open, especially when that enemy was as powerful as Rome, so the strategies of the tribes varied. While some stronger tribes and coalitions like the Nervii were eager to meet the Romans in pitched battle, others like the tribes of Aquitania in south-western Gaul relied more on hit-and-run tactics and attacking the invaders' supply lines as Vercingetorix planned to do during the revolt of 52 BC. Some of the coastal tribes who possessed mobile wealth (usually in the form of cattle) were able to withdraw into marshlands and avoid direct conflict with the Romans, Like the Menapii and Morini of the Channel coast. The Veneti, whose wealth was founded on trade and whose military strength was maritime, based their strategy around defense of hill forts situated on coastal promontories, simply moving by sea to another when one was about to be captured by the Romans. Different tribes, then, had the military capacity to adapt their strategies to deal with the new threat of Rome, and some of these variations were quite successful in impeding Roman progress. Hit-and-run tactics and the avoidance of pitched battle may also have been preferred by Gallic tribes, or necessitated by the absence of the kind of logistical support that Roman armies could depend upon. Large Gallic armies could not remain in existence for very long and unless a decisive engagement quickly occurred, such an army would usually have to disband because of lack of supplies. The Belgic army in 57 BC, which combined many different tribes, was forced to dissipate for this reason when a decisive engagement with Caesar was not forthcoming.
The professional Roman army had many advantages over the armies of the Gallic warrior societies and it was not surprising that several tribes quickly went over to Rome, or that under the leadership of such an effective general as Caesar, the conquest of Gaul was completed remarkably quickly.

Gallic flair and Roman discipline

Gallic and Roman fighting styles were the complete antithesis of each other. For both cultures, victory in pitched battle was the ultimate accolade for a warrior or soldier, and also for tribal chieftains and Roman generals. To show courage on the battlefield was expected; to die in battle was glorious. By the mid-1st century BC, when Caesar began his conquest of Gaul, Romans and Gauls had been fighting each other on and off for centuries. In their literature the Romans betrayed both a fear of their barbarian neighbors, and a sneaking admiration for the way they fought. Gauls were perceived as much larger than Romans (they are portrayed as being of almost giant stature in some accounts); certainly they probably were generally a little taller than the average Italian legionary, and the Romans seem to have been rather defensive about being shorter than their adversaries. Nonetheless, the style of fighting they employed was perfect for fighting Gauls. Indeed, the organization of legions into maniples (120-man units), and the introduction of the large scutum and short gladius as the principal weapons of legionary hand-to-hand combat may have been inspired by conflicts with the Gauls in the 4th century BC.
The Gallic fighting style allowed the warrior to display himself on the battlefield, either through fighting naked or by wearing elaborately decorated armor, and he showed off his valor by fighting as an individual. The warrior's long sword required him to have a fair amount of space around him on the battlefield in order to operate properly. The Celtic sword was essentially a slashing weapon and in the hands of a tall Gallic warrior with a long reach, could be a deadly blade, particularly against shorter opposition with short swords. But the Gallic warriors fought as individuals; though training and especially experience must have provided them with some understanding of tactics, and commands could have been communicated on the battlefield through musical instruments, they did not possess the same degree of training to fight as a unit that Roman soldiers did. When forced to retreat, they could not always maintain ranks and withdraw in good order, something that required considerable training and absolute trust in one's fellow soldiers. This made them vulnerable to outflanking maneuvers and to cavalry attacks on retreating warriors. Lack of space to swing their swords could also cause havoc in the Gallic ranks. When forced together, Gallic warriors could not use their swords properly, and this made them vulnerable to an enemy who could operate at very close quarters with deadly efficiency.
The Roman legionary's equipment did not make him reliant on his neighbor's shield for protection in combat as in a Greek phalanx formation, as he fought as an individual, but he was dependent on the strength of his unit. If his comrades in his century, cohort or legion gave way, he would eventually become exposed to attack on the flank or rear. The might of the Roman army lay in the strength of its formations, and that was based on unit morale, discipline and training. These can clearly be seen when Caesar's legions came under sudden attack by the Nervii in the second season of campaigning. The legionaries did not even need their officers to give them orders: they automatically dropped their entrenching tools, picked up their weapons, and formed a battle line. Their training ensured that even though they were not with their own units and the men they normally fought with, they were resourceful enough to create an effective line of battle. Roman soldiers were not automatons in a 'military machine': they were trained to think and use their initiative as well as follow orders. The training and discipline instilled in the soldiers meant that Roman units could move over battlefields in formation and even retreat while maintaining a defensive formation, an invaluable technique in warfare for minimizing casualties.
In combat with their taller Gallic opponents with their slashing swords, they threw their pila and then moved in very close for hand-to-hand combat. The large scutum protected most of the legionary's front and left side, his short gladius was ideal for stabbing in close-quarter fighting and he could even punch at the enemy with the metal boss of his shield. If the legionaries moved in close enough, they could literally cramp the style of their Gallic opponents while still giving themselves the small amount of room they needed to operate effectively. The short gladius was a brutally efficient tool for killing: a short stab at the torso or especially the belly of his opponent, who may well have been fighting without armor, and he would have been killed or badly injured with damage to internal organs and serious bleeding. Though Roman soldiers were trained to stab with their swords, that did not stop them from slashing with them, and the fine quality and perfect weighting of the gladius meant that they could easily hack off limbs. The average Roman legionary may have been shorter in stature than his Gallic opponent, but his equipment meant he was not at a disadvantage. Moreover, the tactics and fighting style employed in pitched battle against Celtic opponents turned it into an advantage. Usually, in pitched battle Roman discipline triumphed over Gallic flair.

References

Gilliver, K. (2003). Caesar's Gallic Wars. New York: Osprey Publishing Ltd.

Background of Caesar's Gallic Wars

Romans and Gauls had been conflicting for centuries prior to the conquest of Gaul in the 1st century BC, but for long times they had also experienced relative peace as neighbors or near neighbors. Celtic or Gallic tribes (as the Greek writers called them) migrated into northern Italy during the late 5th and early 4th centuries BC, with some tribes settling, mainly around the fertile Po valley. The first major encounter between Rome and these Celtic tribes of what is called as the La Tène culture, came in the early 4th century BC. They enter south into Latium and Etruria (Lazio and Toscana) where the invaders captured and sacked a number of the largest cities, including the important Etruscan center of Veii only a few miles north of Rome.   In 390 BC Rome's field forces were defeated, and the poorly defended city captured by the Gauls. Only the citadel held out: according to tradition, when the Gauls tried to scale it in a surprise night attack, the guard dogs failed to bark and it was only the honking of geese (kept on the Capitol because they were sacred to Jupiter) that awoke the guards. The guards then repelled the attack. The story may not he true, but after sacking Rome, or being paid off by the Romans, the Gauls withdrew. They were defeated soon afterwards by Camillus, the great Roman general who is traditionally recognized by making fundamental changes to the Roman army in order to deal with this new Gallic threat. The sacking of Rome was never forgotten, and Romans remained haunted by a kind of collective inherited fear of hordes of barbarians returning to destroy the city. The sack, along with the long subsequent history of violent encounters between the two cultures, formed part of the background to Caesar's conquest of Gaul.

During the 150 years after the sack, Rome was progressively able to establish superiority over much of the Italian peninsula, ejecting several of the Gallic tribes from lands to the north of Rome. Between the First and Second Punic Wars (during the 3rd century BC this conquest of Italy extended to the north as a coalition of Gallic tribes from northern Italy and across the Alps moved south, only to suffer a devastating defeat at Telamon in 225 BC which broke Gallic resistance in Italy. In the next five years the majority of the territory beyond the Po was incorporated as the province of Cisalpine Gaul, and Roman colonies were founded at Cremona and Piacenza. The final reduction of this new province had to wait until after the Second Punic War and the repulse of the Carthaginian raiding forces under Hannibal. After the first big Roman defeat at the hands of Hannibal at the Trebia in 218 BC, Gallic mercenaries flocked to join Hannibal and served with him through much of the Italian campaign. But after defeating Carthage, Rome turned back to north ltaly and punished the tribes who had fought against them. The whole of ltaly as far north as the Alps was incorporated as Roman territory and further colonies were created at Parma and Bologna. By the middle of 2nd century BC Rome was ready to move into France, having secured her occupation of the whole of Cisalpine Gaul.

Detail from the Altar of Domitius Ahenabarbus, a st century BC relief illustrating the taking of a census which included details of the military liability to every citizen. The two soldiers represent the link between citizen status and military service. (Ancient Art and Architecture)

The reason came in 154 BC when the Greek city of Marseilles requested help from Rome against raids from Liguria. The Roman response included the establishment of a small veteran settlement at Aix en Provence, which irritated the powerful Alloboges tribe nearby, on whose territory it was founded. The Alloboges and their allies, including the Arverni, were defeated in a series of campaigns fought by Fabius Maximus  and Domitius Ahenobarbus. Fabius inflicted an appalling defeat on the Gauls in 121 BC, claiming the quite extraordinary (and highly unlikely) casualty figures of 120,000 Gallic dead to only 15 Roman. The new province of Transalpine Gaul was created, which the Romans frequently referred to as simply 'The Province', from which modern Provence gets its name. As in Cisalpine Gaul, colonies were founded, at Toulouse and Nimes, and a road was built, the Via Domitia, linking Italy with Spain. As well as leading to the creation of another province, the campaign to assist Marseilles also brought Rome into alliance with the Aedui, a Gallic tribe of modern Burgundy who were also allied to Marseilles. The existence of the new province and a formal alliance with the Aedui give Rome with opportunities for further intervention in Gaul and the affairs of the Gallic tribes, but any Further expansion was brought to a sudden stop by the arrival in southern Gaul of the Cimhri and Teutones. These migrating Germanic tribes give serious resistance to Rome, defeating successive consular armies in the late 2nd century BC. They were eventually beaten by Marius (a great Roman general and consul), but as with the Gallic sack of 390 BC, the experience left scars on the Roman psyche. Future Roman attacks and campaigns against Germanic tribes could be passed off as revenge for the defeats and casualties of the 2nd century incursions.

By the 1st century BC several tribes in Gaul were becoming urbanized, especially those in the south where they came under the cultural influence of Marseilles and then, with the establishment of the province of Transalpine Gaul, Rome. Although Caesar uses the word oppidum to describe hill forts, he also uses it for defended settlements that were not on hills. Some of these could have been described as towns even by Romans who might have regarded Gaul and nearly everything about it and its inhabitants as barbaric. Avaricum (Bourges) had an open space which Caesar called a forum and may have had civic buildings; it had a huge defensive wall and its inhabitants regarded it as the most beautiful city in Gaul. Cenabum (Orleans) had a series of narrow streets which may well have had some kind of plan to them: Gallic towns were starting to adopt the grid plans of Mediterranean cities. Evidence of coin manufacture at important oppida suggests that they may have been tribal capitals, indicating some degree of political centralization; Bibracte, for example, seems to have been the 'capital' of the Aedui, who were a fairly centralized tribe although plagued by factions. Other tribes that lacked this degree of centralization might have been considered culturally backward by the Romans, but this added to their military reputation: Caesar considered the Belgae to be the bravest warriors of the Gauls because they were furthest removed from Roman influence. Their lack of centralization also meant that they could be harder to conquer, as Caesar was to find when fighting tribes like the Veneti and Menapii who had no single center of occupation and wealth.

One of the main reasons for the Roman and Greek influence on the Gallic tribes was trade. Marseilles was a significant center of trade, and though Gallic tribes and Rome frequently clashed each other, that did not prevent a huge amount of trade taking place between them well prior to the conquest under Caesar. Romans imported raw materials from Gaul, including iron, grain, hides and, particularly, slaves, the source of the latter being regular inter-tribal warfare that occur between both Gallic and Germanic tribes. In exchange, the Gauls (or at least the Gallic elite) received luxury goods and foods, and enormous amounts of wine. Wine had become a key symbol of wealth, status and 'civilisation', though the historian Diodorus Siculus says that the Gauls drank it neat, rather than diluted with water in the Roman style. Hence, although they were adopting the 'civilized' customs of the Mediterranean, Diodorus makes it clear that they were still barbarians because they did not know how to drink it properly. He goes on to say that wine had become such a valuable commodity that the exchange rate for an amphora of wine was one slave, although there were certainly plenty of slaves around. There must have been many Roman merchants already in Gaul before Caesar's campaigns, including a community of citizens at Cenabum. Some of them were of high status and belonged to the Roman 'equestrian' order, the influential class immediately below senatorial rank, itself a prime source of new senators. They might expect to benefit from the opportunities conquest would bring, especially if they provided assistance in the form of intelligence and supplies for the Roman army.

A sliver coin of the Aeduan leader Dumnorix. The coin shows an Aeduan warrior with a boar standard. Whilst the Aedui were allied to Rome, there were anti-Roman elements within the tribe led by the aristocratic druid Dumnorix, who Caesar called as 'a man of boundless daring'. (AKG Berlin)

Many of the tribes that had come under greater influence from the Roman and Greek cultures to the south were ruled by oligarchies with annually appointed magistrates. The spreading centralization and tendency towards urbanization made such tribes easier targets for Rome, and internal factions within them helped the Romans too. In the mid-1st century BC the Aedui were divided between a pro-Roman faction under Diviciacus, and those who opposed the Romans led by his brother Dumnorix. Dumnorix held a monopoly over the wine trade on the Saône, a tributary of the Rhône. and probably resisted the growing Roman influence for economic as well as political reasons. His influence came from his wealth and his position as a druid: druids held high social status in Celtic society which could bring them political influence. According to the account by Caesar, Dumnorix was attempting to increase his power-base within the Aedui not just because he was opposed to the tribe's pro-Roman stance, but because he was keen to seize power and make himself king. It was important for Rome that the Aedui remained a united and powerful ally of Rome among the Celtic tribes of Gaul, and the squabbling between the two brothers must have given Rome cause for concern.
But the Aedui were coming under pressure from other tribes in Gaul in the 1st century BC. They were a powerful tribe with other lesser tribes under their protection and they had a long-standing rivalry with their neighbors, the Arverni. This rivalry came to a head in 71 BC when the Amerni attacked, along with their allies the Sequani, and German mercenaries from the Suebi whom the Sequani had rather foolishly invited in.  Once the Aedui were defeated the German mercenaries under their king Ariovistus turned on their erstwhile allies and seized much of the Sequanian territory. These events had several consequences. Rome failed to assist her ally, the Aedui, which must have damaged her reputation amongthe Gallic tribes, and Germans were now settling in Gaul near the territory of the Helvetii. This must have seriously worried the Helvetii who had already been forced into Switzerland by earlier migrations of Germanic tribes and they prepared to evacuate their homelands and migrate themselves, to western France.
In 61 BC the Roman senate had confirmed its support for the Aedui, but still failed to act. Romans were expecting some kind of involvement with Gaul in 60 BC though, perhaps military support for the Aedui. Probably because of concern about the huge migration which was obviously about to take place, preparations were made in Rome, including the holding of a levy. During his consulship in 59 BC Julius Caesar had bought off the Suebic king Ariovistus bydiplomatic gifts and the title of Friend of the Roman People. It was not an unusual move for a leading politician to make alliances with kings outside the Roman empire, especially kings of neighbouring territories who might supply additional troops for a campaign. During his year as Consul, Caesar also engineered for himself the appointment as governor of Cisalpine Gaul and Illyricum (the Adriatic coast of Dalmatia); when at the end of the year the governor of Transalpine Gaul suddenly died, Caesar was given that command as well. The forces under his command consisted of one legion based in Transalpine Gaul and three more legions that were in garrison at Aquileia in north-east Italy, based there because of the potential threats from Ariovistus and the Helvetii to the north and the Dacians to the north-east. Caesar may have been planning a campaign against Illyricum initially, but the late addition of Transalpine Gaul to his command opened up a better option.

A barge bang pulled upriver by manpower: Many of Gauls rivers were navigable and provided excellent trade routes, and supply and communication conduits for the invading Roman army Gaulish leader were keen to import luxury goods, such as wine. in return for raw materials such as iron, grain and slaves

Caesar was an ambitious politician and in order to dominate politics as a senator in Rome in the 1st century BC, it helped to be extremely wealthy (to bribe the electorate). to have a great military reputation. Of his two allies and rivals, Marcus Crassus was fabulously rich, and Pompey was both wealthy and Rome's leading general after conquering much of Spain and Turkey. On his appointment as governor of Cisalpine and Transalpine Gaul, Caesar was pretty much broke and had had little opportunity to establish himself as an able general. Conquest of a new province would allow him both to enrich himself and impress the public in Rome with his military ability. There was no doubt at all that Caesar would campaign somewhere and conquer a new province. either on the eastern Adriatic coast or in Gaul. It just happened that there were two convenient pretexts for launching operations in Gaul: the Helvetii began their migration just as Caesar was taking over command, and there was still the matter of Rome's previous failure to support their allies the Aedui. If they requested assistance, particularly against the German King Ariovistus, Caesar could justifiably intervene. At the start of 58 BC the new governor of Cisalpine and Transalpine Gaul was still in Rome when news arrived of the movement of the Helvetian tribes.

References

Gilliver, K. (2003). Caesar's Gallic Wars. New York: Osprey Publishing Ltd.

Caesar's Gallic Wars (58 – 50 BC)

Julius Caesar is possibly the most legendary Roman of all. As dictator, Caesar lead the establishment of the Roman Empire with his nephew Augustus as an emperor, more scandalously, Caesar had a love affair with Cleopatra of Egypt, and even invented the leap year, before being assassinated by colleagues and friends who had in the past supported him. However prior to his dictatorship Caesar had conquered a huge area of Europe during a very short time. The provinces of Gaul invaded by Caesar (Gallia Lugdunensis, Gallia Belgica and Aquitania) are now known as Luxembourg, Belgium, France and Germany to the west of the Rhine, an area of over 300,000 square miles. The political map of much of modern Europe can be traced back to Julius Caesar's 9 years of campaigning. In his battles in Gaul, Caesar also became the first Roman to cross the Rhine at the head of an army, and to cross the Channel to Britain, an island that contemporaries considered a mysterious, terrible and perhaps mythical place.

There is only one detailed account surviving of this amazing war, and this account was written by Caesar himself. As well as being a great, extraordinarily fortunate general and an inspirational leader of men, Caesar was an wise politician fully aware of the importance of self-presentation. In today's terms, Caesar was his own, extremely able spin-doctor. Caesar's De Bellu Gallicu (Gallic War) is the most detailed eye-witness account of war that survives from the Greek or Roman world. Caesar wrote up his commentaries annually and had them published in Rome every year. Everyone in the capital was hungry for news of events in Gaul and there was great excitement at the progress of the war. Caesar made sure they got a one-sided version of events that stressed the magnitude of the Roman victories and his part in them, and underplayed the size and significance of the reverses. The historical reconstruction of the conquest of Gaul must be accomplished using this one extremely biased source, a few brief descriptions in other works of literature written by Romans, and limited archaeological evidence. There is nothing that presents the aims, motives or feelings of the Gauls, except Caesar's interpretation of them, since they had no tradition of recording their history.

The conquest of Gaul occur in the middle of political and cultural change not only in Gaul but also in Rome. By the middle of 1st century BC, parts of Gaul were starting to become urbanized and 'Romanised' when they adopted some of the customs of the inhabitants of the neighboring Roman province of Transalpine Gaul in southern France. Roman traders were very active in Gaul, especially in the southern and central areas, and they also helped to spread their own culture, exchanging “luxury” goods such as wine in return for iron, grain, slaves and hides. Some of the Gallic tribes were developing more centralized forms of organisation, and towns were beginning to grow. Ironically, this helped to make the Roman conquest, when it came, more straightforward: while some of the more “Romanised” tribes such as the Aedui allied themselves to the invaders, some of those who resisted were easier to conquer because they were centralised and had clear centers of occupation and wealth. The tribes with few key occupation centers often had more mobile wealth and resources, and could more easily avoid conquest simply by evading the Romans. Rome itself was sliding towards civil war as a political system designed for a small city-state could no longer manage controlling a huge empire. Leading politicians fought with each other for power and gathered support from their peers, the common people, and the armies that they had commanded when governing Rome's provinces. Military success and loyal soldiers were prerequisites for becoming a leading figure in the power games, and huge areas of the Mediterranean were swiftly conquered by ambitious Romans. Most recently, Pompey, lately returned from the East after a glorious tour of conquest had set new standards for others to imitate. In 59 BC, when Julius Caesar engineered for himself the governorship of Dalmatia and Cisalpine Gaul (northern Italy), there was no doubt that Caesar would conduct campaigns to enhance his military reputation and political future. When the governorship of Transalpine Gaul (southern France) was added to Caesar’s command and the Helvetii in Switzerland began a huge migration, Caesar decided to campaign in Gaul.

In the next few years the Romans made rapid conquests throughout Gaul. The task was made easier by the incapability of the Gallic tribes to unite and form a combined resistance to the invaders. In fact, some tribes supported the Romans, and the Romans themselves played one tribe off against another, exploiting the territorial ambitions of different Gallic tribes and even political divisions in the tribes. Few Gallic armies were able to resist the disciplined and well-equipped Roman legions, and Caesar was able to draw on an increasingly large and experienced army, in addition to allies from Gaul and occasionally Germany to supply him with cavalry in particular. In three years of leading his army into Gaul, Caesar was able to state that the whole province was conquered and lead his army into Germany and across the Channel to Britain, expeditions that provoked shocked admiration back in Rome.

Gaul may have been conquered, but the Gauls were not. The last years of Caesar’s command were spent dealing with sporadic revolts across the province, which were followed, in 52 BC, by a major uprising. Finally the Gauls had found a leader who could unite them: Vercingetorix. The year 52 BC was make or break for both sides: the Gauls pursued a guerrilla campaign of hit-and-run tactics and a scorched-earth policy, while the Romans utilized more sophisticated engineering skills; it also saw two huge-scale sieges of hill forts at Avaricum (Bourges) and Alesia (Alise-Ste-Reine, near Dijon). It was at Alesia that the whole war in Gaul came to a climax, and when the army raised to relieve the besieged Gauls war repulsed, the revolt was effectively over. The relieving army dissolved and Vercingetorix surrendered. Though it was not until the reign of the first emperor, Augustus, that Gaul was properly pacified (and even after that there are indications of the occasional rumble into the middle of 1st century AD, the Gauls were never able to unite effectively again. Gaul became several Roman provinces, evolving after five centuries into the Frankish kingdoms and eventually becoming France. Julius Caesar went on to fight and win a civil war, and make himself dictator of Rome, only to he assassinated in 44 BC

Potrait of Julius Caesar (c. 102-44 BC) the Roman politician and general who conquered Gaul in the middle of 1st century BC.

References

Gilliver, K. (2003). Caesar's Gallic Wars. New York: Osprey Publishing Ltd.