Julius Caesar’s Conquest of Gaul: History, Significance & Other Important Facts

Generally revered as one of history’s greatest military generals, Julius Caesar is best known for his conquest of the vast region of Gaul and later becoming dictator of Rome. His dictatorship ultimately brought an end of the Roman Republic. His military campaign in Gaul ranks up there as one of his greatest military accomplishments.

Who were the Gauls? And how did Rome, under the astute military leadership of Julius Caesar, defeat them?

In the article below, World History Edu provides an in-depth look at how Julius Caesar conquered Gaul and etched his name as one of the greatest military leaders in world history.

Who were the Gauls?

The Gauls were a group of Celtic peoples who inhabited much of Western Europe from the Iron Age through the Roman period. They were particularly concentrated in what is now modern-day France, Belgium, and parts of Switzerland, Italy, and Germany.

The Gauls were known for their fierce warrior culture and were feared by the Romans for their military prowess. They were also skilled metalworkers and artisans, creating intricate and ornate objects such as jewelry, weapons, and sculpture.

Also, the Gauls minted their own coins. This practice began around the 4th century BC and ended in the 1st century AD, when Gauls had been fully assimilated into the Roman Empire. It was often the case that the Celtic coins minted by the Gauls copied the design and features of Greek coins. It is said that the Macedonian coins from the era of Philip II of Macedon and Alexander the Great had strong influence on Gaulish coins. The usual images found on the coins were their leaders, generals, and some mythical deities and figures.

Julius Caesar’s rise to political power in Rome

Julius Caesar was born into an affluent and influential family – the gens Julia. His family claimed to be descendants of Julus (also known as Ascanius), the legendary king of Alba Longa and son of Trojan War hero Aeneas and Creusa. As Aeneas was seen as the son of the Roman goddess Venus (Aphrodite in Greek mythology), the Julii saw themselves as descendants of the goddess of Venus.

In his early youth, he served as high priest of Jupiter (flamen Dialis). As high priest, he was not allowed to coming into contact with a horse, touch a metal, or see a corpse.

After his uncle Gaius Marius lost out on a power struggle to Lucius Cornelius Sulla, Julius Caesar was stripped of many of his possessions and titles, including the high priest role. This allowed him to pursue a military career. He went on to serve under the command of Roman generals like Marcus Minucius Thermus and Servilius Isauricus. Right from the get go, he proved to be a capable military officer, even earning the Civic Crown, a military decoration given to officers that saved the lives of citizens.

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Prior to his election as quaestor in 69 BC, he served as a military tribune. Also in 69 BC, he lost his first wife Cornelia.

In 68 BC, he displayed his oratory prowess to the maximum by giving a powerful funeral oration for his aunt Julia. Julia was the wife of Roman general and statesman Gaius Marius. The oration was titled laudatio Iuliae amitae (“Eulogy for Aunt Julia”).

In 67 BC, he tied the knot with Pompeia, the granddaughter of Sulla. The marriage lasted until 61 BC when the couple got a divorce.

After serving as praetor in 62 BC, he became the propraetor of Hispania Ulterior. His military and civilian exploits in Hispania earned him enormous acclaim. Such was the acclaim that his troops started calling him imperator in honor of his conquest of a number of local tribes.

In 60 BC, he had to make a decision between receiving a Roman triumph, a very high military accolade from the Senate, or becoming a consul. He chose the latter and was elected consul in 59 BC. His political ascent was facilitated by the financial support he received from Marcus Licinius Crassus, Rome’s wealthiest man at the time.

Having gained the financial support of Crassus, Caesar sought to boost his political standing by aligning himself to Pompey the Great, an influential Roman general and politician. Unfortunately, Pompey and Crassus did not see eye to eye; therefore, Caesar set out to act as an intermediary between them. By 60 BC, he had successfully managed to bring Pompey and Crassus into a political alliance. The three men then went on to form an unofficial political alliance called the First Triumvirate, which means “rule of the three men”. To cement the ties, Pompey tied the knot with Julia, Julius Caesar’s daughter.

As the First Triumvirate became more and more influential so did their appeal to the public. This was because they used their political and financial almost to the interest of the public. For example, reforms were passed for the redistribution of public lands to the poor. As consul, Caesar also managed to take fellow consul and opponent Marcus Bibulus out of the picture. This explains why some Roman satirists at the time termed that year’s consulship as one of Julius and Caesar.

Governorship over Cisalpine Gaul, Illyrium, and Transalpine Gaul

Try as Caesar’s opponents in the Roman Senate might, they simply could not halt the political rise of Caesar following the end of his consulship. Caesar carefully leveraged his political connections and secured governorship over Cisalpine Gaul (present-day northern Italy) and Illyricum (northwest Balkans). And when the governor of Transalpine Gaul (southern France), Metellus Celer, died, Caesar was made governor of the province. Known as Provincia Nostra, the province was the first north of the Alps.

His time as governor of the province witnessed many progress, including the rebuilding of the capital Narbonne and the cities of Arles and Forum Julium. He also made many of the inhabitants citizens of Rome.

Caesar also set out to secure his finances by embarking on military adventures. His provinces shared border with a number of territories that had not being conquered by Rome. With some Gallic tribes in those territories experiencing social turmoil, Caesar hoped to capitalize fully on the situation. Rome also became suspicious of the Germanic tribes in the region. Therefore Caesar embarked on a campaign against them.

The combined total of the forces in the four legions – the Legio VII, Legio VIII, Legio IX Hispana, and Legio X – under his command were more than 20,000 legionaries plus auxiliaries.

Reasons why Julius Caesar began his military conquest of Gaul

In his own account (i.e. Commentarii de Bello Gallico), Julius Caesar enumerated some of the reasons why he began a military campaign against the Gauls. The Roman general cited reasons such as it being a preemptive strike – a sort of deterrent to the Gauls, whom he believed were mobilizing and preparing to strike Roman border regions.

However, the true reason for his campaigns against the Gauls was to get himself out of pile of debt – debt he had incurred during his political campaigns in Rome for the position of consulship in 59 BC. In the end, he raked a lot of fortune from plundering Gallic territories.

Also, Caesar, having been given a five-year term as proconsul and governor of those regions, believed that he had reasonable amount of time to embark on a proper military campaign against the Gauls. He reasoned that a victory over the Gauls would boost his political fortunes and turn him into a hero among the people.

Right from his teen years, Julius Caesar had always had big admiration for the likes of Philip II of Macedon and Alexander the Great. He marveled at how a relatively young general as Alexander could pull of such massive military victories and conquest.

Therefore, his military campaigns against the Gauls was his way of following in the footsteps of Alexander. Caesar dreamed of one day having Rome in the palms of his hand. The military conquest was seen by Caesar as his ticket to legendary status and a launching pad to attaining that goal.

What triggered the Gallic Wars?

Before the breakout of the Gallic Wars in 58 BC, Rome’s Gallic ally Aedui was attacked by an alliance of the Gallic tribes Arverni and Sequani and the Germanic Suebi nations. The Aedui suffered a crushing defeat at the Battle of Magetobriga in 63 BC. The Aedui’s request for aid from Rome did not get any reply. However, Julius Caesar would later use the attack on Aedui by the Gauls as one of the pretext to begin his campaigns against the Gauls.

Some scholars have stated that Caesar’s original plan was to invade the Balkans and the Dacians; however, he changed his mind following a mass migration of the Helvetii in 58 BC. The Helvetii tribes, who were predominantly based on the Swiss plateau, were fleeing from Germanic tribes to the north and the east. Their goal was to make it to the west coast of northern Italy.

Also, there were fears among Romans that the migration of Helvetii would cause other Gallic tribes to also migrate, at which point, the Germanic tribes would then occupy the lands vacated by the Gallic tribes.

58 BC: The start of the Gallic Wars

Julius Caesar would use the migration of those Gallic tribes as a justification for a military campaign against the Gauls. Caesar marched about five of his legions and unleashed an unprovoked attack against the Helvetii. The Roman general had an estimated total of between 25,000 and 30,000 soldiers. It must be noted that Gauls formed part of some Caesar’s auxiliaries.

Upon arriving at the river Saône, which is in eastern France, Caesar’s forces slaughtered many Helvetii that tried to cross the river. He tasked his engineers to make a pontoon bridge, which he used to go across the river in order to push deep into Gallic lands. He made his way to Bibracte, the capital of Rome’s allies the Aedui.

At Bibracte, the Helvetii, with support from Gallic allies like Tulingi and Boii, decided to launch an attack against Caesar’s forces. Known as the Battle of Bibracte, Caesar fielded six Roman legions – Legio VII Claudia, Legio VIII Augusta, Legio IX Hispana, Legio X Equestris, Legio XI Claudia, and Legio XII Fulminata.

With relatively greater number of forces, Caesar managed to overpower and force the Helvetii to flee for some time until the Boii and the Tulingi tribes made their way into the battlefield. By the end of the battle, the Romans were the outright victors, and they even captured took many Helvetii prisoners, including the two children of Orgetorix, an influential aristocrat of the tribe. After being pursued for a while by Caesar’s forces, the Helvetii surrendered to Caesar.

According to Casaer’s own account, the battle saw the Gallic tribes field more than 360,000 forces. This figure might have been exaggerated. According to Roman priest and historian Orosius, the Gallic forces at the Battle of Bibracte numbered around 157,000, and that almost 50,000 perished at the battle. However, modern historians often like to place the figure between 10,000 and 15,000.

Julius Caesar’s military victories against the Helvetii caused other Gallic tribes and Germanic tribes to enter the war. One of the Germanic tribes that entered the fray was the Suebi. For many years, Rome and Ariovistus, king of the Suebi, had good ties.

Therefore, Caesar needed a very good reason to wage war against the Suebi. He found it in the form of the Suebi’s conquests of some territories belonging to the Aedui, who were one of Rome’s most loyal Gallic allies. In the ensuing confrontation between Ariovistus and Caesar – i.e. the Battle of Vosges in 58 BC – the Romans with six legions defeated the Germanic tribes. Publius Crassus, the son of Marcus Crassus, distinguished himself brilliantly in the battle.

In the accounts of Caesar, the number of Germanic forces killed in the battle was placed at around 120,000 – this is once again an exaggeration by the Roman general.

Caesar pushes on to conquer all of Gaul

Following those two remarkable victories over the Gallic and Germanic tribes, Caesar reasoned that the winds were in his sails and therefore set out for an-out conquest of all of Gaul. Sensing this, some Gallic tribes quickly struck an alliance with Rome.

In 57 BC, he marched his army against the Belgae tribal confederation (in what is today’s Belgium). The Belgae had attacked a Gallic tribe allied with Rome, and Caesar decided to intervene. Once again, Caesar’s forces proved to be mightier than the Belgae, resulting in the latter surrendering. The capitulation of the Belgae sent a lot of shocks throughout the region, causing the likes of the Ambiones and Bellovaci to surrender.

However, there were some Belgic tribes that continued to remain defiant. One such group was the Nervii, who had struck an alliance with other Belgic tribes like the Viromandui, Atrebates, and Aduatuci. The Nervians and their allies faced off against the Romans in 57 BC in northern France. Up until then, Caesar had not faced such a stern opposition as the one put up by the Belgae tribes at the Battle of the Sabis.

With cunning military tactics and the timely arrival of reinforcements, Caesar and his eight Roman legions managed to snatch a victory from the jaws of defeat. After the battle, more Germanic tribes sued for peace with Rome.

By this time, Caesar had not only gathered a lot of money from the wars to pay off his debts, but he had also cemented himself as one of Rome’s greatest generals. The Senate duly honored him with a 15-day supllicatio (i.e. a thanksgiving).

Caesar’s naval campaign against the Veneti

Located in the northern part of the Brittany Peninsula, the Gallic tribe of Veneti in the winter of 56 BC refused to comply with Caesar’s orders to provide grain and housing for the Roman troops.

As they duly anticipated a fierce response from Caesar, the Veneti proceeded to ally themselves with the tribes of Armorica (or Aremorica), a group of Gallic tribes that inhabited regions between the Seine and the Loire in France.

The two tribes worked around the clock preparing a fleet that could take on the Romans. Unlike the Romans who used oarsmen, the Veneti used sails. In the initial stages of the naval battle (i.e. the Battle of Morbihan in 56 BC), the Veneti ships proved to be well-suited to the region.

However, the Roman ships, which were fitted with grappling hooks, proved to be a big advantage. Those hooks could wreck the opponent’s ship. As the battle progressed, the Romans began to gain an upper hand, forcing the Veneti fleet to retreat. Roman ships pursued and caught up with the Veneti fleet, at which point, Roman soldiers boarded the opponent’s ships and proceeded to slaughter them en masse.

The naval battle against the Veneti ended up being a stunning victory for Caesar, who took no mercy on the leaders of the Veneti. The Roman general slaughtered every one of them and then sold a significant number of the Veneti population into slavery.

In the months that followed, Caesar’s trusted generals like Publius Crassus and Quintus Titurius Sabinus managed to bring southwest Gaul and Normandy under Roman control.

In April 56 BC, at the Luca Conference near Pisa (located in present day Tuscany, central Italy), the First Triumvirate pledged their commitment to the political alliance. It was agreed that Pompey and Crassus would stand for the consulship in 55 BC. It was also decided to extend Caesar’s command in Gaul by an additional five years.

By 55 BC, Caesar standing in the public had tremendous shot up. Buoyed on by the victories against the Gauls, the Roman general decided to embark on military expedition never undertaken by any Roman general. Caesar went on expeditions across the Rhine and the English Channel.

Caesar becomes the first Roman general to cross the Rhine

He crossed the Rhine primarily because he wanted to halt the advances of made by the Celtic Tencteri and Usipetes across the Rhine. Those tribes had been forced out of their territories by the Suebi.

In the first few skirmishes, the Celts outwitted the Romans and defeated them. Sour by the loss, Caesar attacked civilian population of the Celts.

According to his account, he killed 430,000 Celts in that campaign. His attacks against civilians drew the ire of the Roman Senate who considered the general’s actions nothing short of war crimes. The only thing that saved him from prosecution was the immunity he enjoyed as governor.

Following those attacks on the civilians, Caesar proceeded to cross the Rhine. The campaign across the Rhine was aimed at making him appear a hero to the Roman public.

It is said that it took Caesar’s engineers less than two weeks to build a timber bridge, which he used to cross the Rhine. Once across the Rhine, Caesar and his forces raided a number of Suebic settlements.

Caesar and his forces, however, had to pull back just before the Suebi could regroup and put up a fight. He made sure that the bridge he built across the Rhine was destroyed completely.

By building the bridge, Caesar firmly demonstrated Rome’s power and Rome’s ability to cross the Rhine at their pleasing. No longer would the Rhine keep the Germans away from the fury of Rome. It was also a significant moment in history as never before had a bridge spanned the Rhine.

Poor harvests in 54 BC leads to some Gallic tribes revolting against Rome’s control

Upon his return from his invasion of Britain, Caesar kept his troops in Gaul areas and required them to provide grains to his troops. The situation was made worse as that year’s harvest was very bad. With not enough food to go around, Gallic tribes began to grow very frustrated at Caesar.

Caesar ordered his troops to spread out among the various Gallic tribes so that there won’t be a lot of pressure on one Gallic tribe. Regardless, the discontent among the Gauls was still palpable. Soon, that discontent morphed into rebellions. One of such tribes to rebel was the Eburones, who were led by Ambiorix. Known as a prince of the Eburones, Ambiorix was opposed to Caesar’s forces wintering in his tribe. The Belgic leader took to ambushing and killing Roman forces.

When news of Belgic uprising reached Caesar, the Roman general mobilized his legions and marched to the aid of Roman forces that were under attacks from the Belgic tribes. For their revolt, Caesar exacted a harsh punishment on the Belgic tribes. He carried out mass killings in the Eburones, which ultimately resulted in the tribe disappearing from the annals of history.

Ambiorix was able to convince Roman general Sabinus that all of Gaul was revolting. Ambiorix also lied to the Romans that the Germanic tribes were preparing to march into the region. The Belgic chieftain offered to provide the Romans a safe passage back to Rome.

Instead, Ambiorix ambushed the Romans, killing many Roman forces, including Sabinus and Cotta. The actions of Ambiorix emboldened the Gallic tribes like Nervii and Atuatuci to also rebel.

When news of the Gallic revolt against Rome reached Caesar, who mobilized his forces and marched to support Roman forces that were under siege in those rebellious Gallic areas. For example, he arrived just in time to prevent the total annihilation of Roman troops under the leadership of Quintus Cicero.

The Gallic uprisings against Rome in 54 BC caused the destruction of one of Caesar’s legions. Even before winter was over, Caesar, having received two more legions, went on the offensive. He raided many Gallic tribes and sold many of them into slavery. He secured the surrenders of the Nervii, the Senones and the Menapii.

How Caesar dealt with Vercingetorix’s revolt in 52 BC

In 53 BC, Caesar made an announcement that the Gauls were to be brought in as a province of Rome. What that meant was that they would be governed by Roman laws and abide by Roman religious practice. This decision posed a huge threat to the Gauls, who felt that Rome was out to wipe their culture and destroy their lands.

Vercingetorix, leader of the Arverni tribe, took it upon himself prevent Gaul from becoming a province of Rome. He realized that the various Gallic tribes had a chance to oppose Rome if they came together and worked as a unit.

Vercingetorix worked hard to form an alliance of Gallic tribes and took the fight straight to the Romans. Under his leadership, the Gauls secured victory at the Battle of Gergovia in 52 BC.

Unfazed by the defeat at Gergovia, Caesar continued to recruit more and more Gauls into his army.

When the Romans threatened Alesia, which was the capital of the Mandubii, Vercingetorix was quick to come to the city’s aid. Considered the last major engagement between the Romans and the Gauls, the Battle of Alesia in 52 BC saw Caesar’s forces defeat Vercingetorix.

Caesar’s engineers produced some very impressive siege works that proved to be very advantageous during the battle. At the end of the battle, Vercingetorix surrendered to the Romans and was later taken prisoner.

The defeat suffered by the Gauls at the Battle of Alesia meant that their years of being independent were over. Almost all of the Gallic tribes had surrendered to the Romans.

Julius Caesar purposely left his troops wintered across Gaul just so to prevent any rebellion from happening. Some of Caesar’s legions remained active in the region in order to maintain Rome’s rule in the area.

Did you know…?

Some scholars note that had Julius Caesar’s Civil War not broken out in 49 BC, Caesar would most likely have continued his military campaign into Germanic tribes.

Significance of Caesar’s conquest of Gaul

The Gauls, although partly subjugated by Rome in the late 50s BC, would only become a province of Rome in 27 BC, which was during the reign of Emperor Augustus, Rome’s first emperor and the grandnephew of Caesar.

Rome’s conquest of Gaul had a tremendous impact on the Gallic people and their culture. The region remained under Roman rule for about five centuries, influencing the religion, language and artworks of Gallic tribes. For example, the language of the Gauls – i.e. Gaulish – went extinct by the 6th century AD. The region used Vulgar Latin during the Roman era. That language would later evolve into Old French, which formed the basis of modern French language.

Also the conquest of Gaul allowed future Roman emperors – like Augustus and Claudius – to push further into Germania and even Britain. For example, almost a century later, in 43 BC, Roman emperor Claudius led Rome’s conquest of Britain. Rome would remain the dominant power in mainland Europe until the early 5th century AD when a mixed group of barbarians – including the Vandals and Alans – crossed the Rhine and began laying waste to Roman cities.

Read More: Top 10 Greatest Roman Emperors

In addition to aiding Julius Caesar out of a deep financial debt, the Gallic Wars (58-50 BC) in a way hastened the end of the Roman Republic. Following the end of the war, Caesar refused to disband his army and return to Rome to face trial.

Instead, the Roman general marched his legions on Rome, ushering in a 5-year bloody civil war (i.e. Caesar’s Civil War). In the aftermath of the Civil War, which he won against Pompey, Caesar managed to rise to the status of dictator for life.

Just how inaccurate was Julius Caesar’s account of the Gallic Wars?

There are not too many sources when it comes to the Gallic Wars and how Julius Caesar conquered the Gauls. Much of what we know about the conflict comes from an account by Julius Caesar himself – his book Commentarii de Bello Gallico. And saying that the general’s description of the events of the war was biased would be an understatement. Today, we know that Caesar’s account of the war has very minimal historical accuracy; however, for many centuries, it was seen as infallible.

A master propagandist, Caesar intentionally exaggerated his efforts in the Gallic Wars in order to enhance his standing in the public. In many of the battles, he claimed that several thousands of Gauls were killed and that not a single Roman soldier died.

Caesar placed the number of Gaul fighters in the war at almost a million, stating that he could estimate this figure based on extrapolations made from the population census figures of the Gauls at the time. For example, he once stated that the population census figures were written in Greek on tablets he found in the camp of the Helvetii. The Roman general then conveniently stated that one quarter of the Helvetii population were combatants. Such an assertion should be taken with a lot of skepticism because:

• First, why would the Gallic tribe of Helvetii go to battle carrying a heavy tablet of their population census?
• Second, why did a non-Greek tribe as that of the Helvetii write their population census figures in Greek?

Roman historian Titus Livius (popularly known as Livy) estimated that the Helvetii’s population was in the region of 157,000. According to modern historian Hans Delbrück (1848-1929), it’s more likely that that total number of combatants fielded by the Helvetii was 12,000.

There is no doubt whatsoever that Julius Caesar exaggerated the total numbers of the Gaul combatants in the war. For example, he stated that his forces faced off against a combined force of about 430,000 Usipetes and Tenceri. The general also made the absolutely ludicrous claim that no Roman life was lost in the battle.

Caesar’s account of the war in his book Commentarii de Bello Gallico was simply a clever piece of propaganda aimed at elevating him to a legendary status. We know this for fact because of the outlandish figures, in terms of enemy combatant and casualties, he stated in the book.

Understating the losses suffered by Rome during the Gallic Wars was designed to make the Romans appear as a superior fighting force that was imbued with the strength of the Roman gods.

Caesar knowingly provided a biased interpretation of the events of the Gallic Wars in order to influence Rome’s opinion and to paint the Gallic people as “barbaric” heathens. Considering the fact that his account of the war did not meet any stern challenge until the late 19th and early 20th century showed just how much of a spin doctor he was.

Today, we know for a fact that the Gallic tribes were not the “barbarians” that ancient Rome authors, including Julius Caesar, had us believe. Instead, they were very capable fighters that came from a society almost similar to that of the Romans. They Gauls had large cities and complex political systems, almost comparable to the ones Rome had. By gaining control the lands of the Gauls, Rome benefited tremendously from the vast wealth of the region.