Gallic Wars

The Gallic Wars were a series of military campaigns fought between 58 and 50 BCE by the Roman proconsul Julius Caesar against the peoples of Gaul and some of their neighbours. At the start, Rome already controlled the Mediterranean coast of southern France (the province of Gallia Narbonensis) and northern Italy (Cisalpine Gaul). By the end, all of Gaul between the Pyrenees, the Alps, the Atlantic and the Rhine had been brought under Roman power.

The wars were not a single war against a single enemy. Gaul was divided among dozens of independent peoples, and Caesar often fought with some of them as allies against others. Only in 52 BCE did a broad coalition under Vercingetorix try to drive the Romans out.

The Gallic Wars matter because they transformed western Europe, made Caesar the most powerful man in Rome and led directly to the civil war that ended the Roman Republic. They also produced one of the most famous books in Latin literature, Caesar's own account, which begins: “All Gaul is divided into three parts.”

Caesar described Gaul as divided into three parts, inhabited by the Belgae in the north, the Aquitani in the southwest and the people who called themselves Celts, whom the Romans called Gauls, in the centre. This was a simplification. There were perhaps sixty or more peoples (civitates), such as the Aedui, Arverni, Sequani and Helvetii, each with its own territory, aristocratic leaders and assemblies. Rivalries between them, especially between the Aedui and the Arverni and Sequani, were intense.

Archaeology shows that Gaul in the second and first centuries BCE was far from the wild land of barbarian stereotypes. Many peoples lived in large fortified towns called oppida, such as Bibracte (Mont Beuvray) and Gergovia, with streets, workshops, coinage and long-distance trade. Gauls imported large amounts of Italian wine and some wrote their own language using Greek letters.

Gallic religion was led by the druids, an educated class who, according to Caesar, served as priests, judges and teachers. Much of what we are told about them comes from Caesar's Book 6 and later Greek and Roman writers, so the picture is partial.

As consul in 59 BCE Caesar, in alliance with Pompey and Crassus (the so-called First Triumvirate), obtained an unusually long five-year command over Cisalpine Gaul and Illyricum; the Senate then added Transalpine Gaul. He was deeply in debt from his political career, and a great war would bring him plunder to pay his debts and reward his supporters, a loyal army, and the glory needed to rival Pompey.

The immediate occasion came in 58 BCE when the Helvetii, a people of what is now Switzerland, planned to migrate west through Roman territory. Caesar refused them passage, then followed them into the territory of the Aedui, Roman allies, and defeated them near Bibracte. Next, at the request of Gallic leaders, he turned against Ariovistus, a Germanic king of the Suebi who had settled west of the Rhine, although the Senate had recognized Ariovistus as a “friend of the Roman people” only the year before, during Caesar's own consulship.

In his Commentarii Caesar presents each campaign as a defensive response to threats against Rome or its allies. Most modern historians see these justifications as partly genuine and partly constructed, and agree that the conquest of all Gaul served Caesar's personal political needs as much as Rome's security.

Caesar began in 58 BCE with four legions, quickly raised two more, and by 52 BCE commanded ten or more, some of them recruited on his own authority in Cisalpine Gaul. A legion was nominally about 5,000 heavy infantry, though units in the field were often under strength. Alongside them fought auxiliaries: Numidian and Cretan archers, Balearic slingers and, above all, cavalry supplied by Gallic allies and, from 52 BCE, hired Germanic horsemen. His most important deputy was Titus Labienus, who later joined Pompey in the civil war.

On the other side there was no single enemy. Gallic peoples were led by aristocrats with bands of retainers, and their cavalry was highly regarded; their infantry was brave but harder to hold together in long campaigns. Some peoples, such as the Remi in the north and for most of the war the Aedui, were Roman allies who gained from Caesar's victories over their rivals. Inside many peoples, factions also divided over whether to cooperate with Rome, and Caesar often installed or supported friendly leaders.

This complexity matters for understanding the war. Caesar's conquest was made possible in part by Gallic divisions and by Gallic soldiers who fought on his side, and the great revolt of 52 BCE was remarkable precisely because it briefly overcame those divisions.

58 BCE: Caesar defeated the Helvetii and drove Ariovistus back across the Rhine. According to Caesar, only about 110,000 of 368,000 Helvetii returned home; modern scholars consider his figures greatly exaggerated. 57 BCE: he campaigned against the Belgic peoples of the north. At the river Sabis (probably the Sambre) the Nervii surprised his army and nearly destroyed it before Caesar rallied his troops. After the siege of the Aduatuci, Caesar says he sold 53,000 people into slavery.

56 BCE: the Veneti of Brittany, a seafaring people, detained Roman officers. Caesar built a fleet, defeated them at sea, executed their council and sold the rest of the population into slavery. That year Caesar's allies met at Luca and arranged a five-year extension of his command. 55 BCE: when two Germanic peoples, the Usipetes and Tencteri, crossed the Rhine, Caesar detained their envoys during negotiations and attacked their camp, killing men, women and children; he gives the implausibly high figure of 430,000 for their people. In Rome, Cato proposed that Caesar should be handed over to the Germans for breaking faith. Caesar then built a bridge across the Rhine in ten days as a show of power and made a brief expedition to Britain.

54 BCE: a larger expedition to Britain forced the British leader Cassivellaunus to give hostages and promise tribute. That winter, Ambiorix of the Eburones tricked a Roman garrison into leaving its camp and destroyed it, killing about fifteen cohorts, while other Gauls besieged the camp of Quintus Cicero until Caesar relieved it. 53 BCE: in reprisal Caesar devastated the land of the Eburones and invited neighbouring peoples to plunder it, aiming, in his own words, to wipe out their name. Ambiorix escaped and was never captured.

In early 52 BCE, while Caesar was in Italy, Gallic rebels killed Roman traders at Cenabum (Orléans). The young Arvernian noble Vercingetorix was proclaimed king by his supporters and built an alliance of many Gallic peoples. His strategy was to avoid pitched battles, burn farms and towns so that the Romans could not find food, and attack their supply lines.

The Bituriges could not bear to burn Avaricum (Bourges), their finest town, and it was defended instead. Caesar besieged and stormed it; he says that of about 40,000 people inside, barely 800 escaped. Caesar then attacked Gergovia, the main oppidum of the Arverni, but his assault failed with heavy losses, the most serious defeat he suffered in person in Gaul. Even the Aedui, Rome's oldest allies in Gaul, now joined the revolt.

Vercingetorix then withdrew with his army into Alesia, a hilltop oppidum of the Mandubii. Caesar surrounded it with an inner line of fortifications about 15 km long, and an outer line of about 20 km facing outward against a relief army. The Mandubii expelled their women, children and elderly to save food; Caesar refused to let them pass, and they were left between the lines, where they presumably died. A great Gallic relief army, which Caesar puts at 250,000 infantry and 8,000 cavalry (numbers modern historians doubt), attacked from outside while Vercingetorix attacked from within, but after several days the Romans broke both attacks. Vercingetorix surrendered.

Caesar distributed captives as slaves to his soldiers, one per man, except for the Aedui and Arverni, whom he released to win back their loyalty. Vercingetorix was held for six years, displayed in Caesar's triumph in Rome in 46 BCE, and then executed.

Resistance continued in 51 BCE. At Uxellodunum, in southwestern Gaul, Caesar cut off the defenders' water supply; after they surrendered, according to Book 8, he had the hands of all who had borne arms cut off, as a warning to others. By 50 BCE Gaul was largely pacified, and in January 49 BCE Caesar crossed the Rubicon with his army, beginning the civil war against Pompey and the Senate.

For Gaul, the immediate consequences were devastating. Ancient writers give enormous figures: Plutarch says Caesar fought three million people, killed one million and enslaved another million, and Pliny the Elder puts the number killed in Caesar's wars (excluding civil wars) at 1,192,000. These numbers cannot be verified and are probably inflated, but the destruction of towns, the massacres of entire communities and the mass enslavement described by Caesar himself leave no doubt that the human cost was immense. Caesar imposed a tribute that Suetonius puts at forty million sesterces a year.

In the long term, Gaul became one of the most important parts of the Roman Empire. Under Augustus it was organized into provinces; cities such as Lugdunum (Lyon) became centres of Roman administration; Gallic aristocrats gained Roman citizenship, and under the emperor Claudius some entered the Roman Senate. Latin gradually replaced the Gaulish language, and from it French and other Romance languages developed. For Rome, the conquest shifted the empire's centre of gravity toward western and northern Europe.

For Romans and for European elites for centuries afterwards, the Gallic War was Caesar's achievement, read as a model of military leadership and of clear Latin prose. Generations of schoolchildren learned Latin from the Commentarii, often without considering the Gallic side of the story.

In nineteenth-century France, historians such as Amédée Thierry turned the Gauls into national ancestors, and Vercingetorix became a symbol of resistance to foreign conquest. Emperor Napoleon III sponsored excavations at Alise-Sainte-Reine in the 1860s, wrote a history of Julius Caesar, and in 1865 had a colossal statue of Vercingetorix erected there. After the defeat of 1870–71 by Prussia, Vercingetorix was used as a figure of heroic defeat and future revenge, and Third Republic schoolbooks spoke of “nos ancêtres les Gaulois” (our ancestors the Gauls), a phrase later repeated even to colonized children in Africa and Asia. The comic series Astérix, begun in 1959, turned the theme into gentle humour.

Other countries have their own memories. In Belgium, Caesar's remark that the Belgae were the bravest of the Gauls and the figure of Ambiorix, whose statue has stood in Tongeren since 1866, became part of national identity. In Britain, Caesar's expeditions are often treated as the beginning of the island's written history. Modern scholars and museums, such as the MuséoParc Alésia and the archaeological centre at Bibracte, increasingly present the war from Gallic as well as Roman perspectives, and many historians now describe it frankly as a war of conquest marked by mass violence.

The main source is Caesar's Commentarii de Bello Gallico, seven books covering one year each from 58 to 52 BCE, written in a plain, apparently objective third-person style. Cicero praised them as “bare, upright and graceful”. Book 8, covering 51–50 BCE, was added after Caesar's death by his officer Aulus Hirtius. Scholars debate whether Caesar sent reports to Rome year by year that were later collected, or wrote the whole work quickly in 52–51 BCE; in either case it was meant to influence opinion in Rome while he was absent.

Caesar's account is both indispensable and self-serving. He justifies each campaign, emphasizes the dangers and his own speed and clemency, blames defeats on subordinates, and gives enemy numbers that are often implausibly large. Already in antiquity, according to Suetonius, Asinius Pollio thought the Commentarii were written with little care for accuracy. The ethnographic passages on the Gauls, Germans and Britons, especially in Books 5 and 6, are valuable but shaped by Greek ethnographic tradition and by Caesar's aims.

Other sources are later and derivative: Plutarch's Life of Caesar, Suetonius, Appian (fragmentary), Cassius Dio and a few remarks in Cicero's letters, some written by his brother Quintus, who served in Gaul. No account by a Gaul survives. For the Gallic perspective historians rely on archaeology, coins struck by Gallic leaders, including Vercingetorix, and critical reading of Caesar against the grain.

Locating the battles has been a long scholarly project. Napoleon III's excavations at Alise-Sainte-Reine found ditches, weapons and coins, but the identification of Alesia was disputed for more than a century, with rival sites such as Chaux-des-Crotenay in the Jura. Franco-German excavations in 1991–1997 confirmed the Roman siege works at Alise-Sainte-Reine to the satisfaction of most specialists, while showing that Caesar's description had been simplified. Gergovia has been located on a plateau near Clermont-Ferrand, and Uxellodunum is generally identified with the Puy d'Issolud, where many Roman arrowheads and traces of the tunnels used to cut the spring have been found.

The scale of violence is a central debate. Some historians have described Caesar's treatment of the Usipetes and Tencteri or the Eburones, where Caesar himself says he aimed to destroy a whole people, as genocidal; others caution against applying modern legal categories to ancient warfare or against trusting Caesar's inflated numbers. Recent archaeological work, including the discovery reported in 2015 of mass remains near Kessel in the Netherlands that the excavators linked to the massacre of 55 BCE, has brought new evidence into this discussion, although such identifications remain debated.

A further debate concerns the nature of Gallic society and the effects of conquest. Older views saw the conquest as bringing civilization to barbarians; archaeology of the oppida shows a society already undergoing urbanization and state formation, closely connected to the Mediterranean economy. Historians now ask how Gallic elites negotiated with Roman power, how much of Gallic culture survived under Rome, and how far the image of a united “Gaul” was itself a creation of Caesar's narrative.