On 30 September-3 October 52 BCE, the Battle of Alesia was fought between the Romans under Julius Caesar and the Gauls under Vercingetorix during the Gallic Wars.
Why did it happen?
In 58 BCE, the Romans, under Gaius Julius Caesar, began the conquest of Gaul (modern-day France). By 53 BCE, Caesar had subdued most of Gaul from southern France to the North Sea Coast and had even invaded Britain twice in 55-54 BCE. However, in 52 BCE, a Gallic leader named Vercingetorix managed to unite the Gallic tribes and undo Caesar’s conquests. Vercingetorix defeated Caesar at the Siege of Gergovia in May but became besieged by Caesar's forces inside the hilltop fortress of Alesia in July. Before Caesar could complete his siege fortifications around Alesia, 15,000 Gallic cavalry managed to break through and call upon reinforcements. By the time reinforcements arrived in late September, Caesar had built a second wall around Alesia. However, he was heavily outnumbered.
Who was involved?
The Roman army at Alesia numbered 40,000 infantry and 5,000 cavalry. Most of Caesar’s army was positioned behind the walls in camps and forts surrounding Alesia. The Gallic army at Alesia numbered 10,000 infantry and 8,000 cavalry, with another 80,000 reinforcements, giving the total size of the Gallic army to 98,000 men. Caesar claimed that the Gallic forces numbered 80,000 under Vercingetorix and 250,000 in the relief army, but this is almost certainly an exaggeration. However, it is possible that the excess of 80,000 could have included women and children, who were sent out due to low supplies to try and be admitted past the Roman lines. When Caesar refused, they starved to death in the no-man’s land between both armies.
What happened?
On 30 September, three months into the siege, a Gallic relief army under Commius and Vercassivellaunos arrived and skirmished with the Roman army throughout the day. On 1 October, Commius attacked the Roman walls surrounding Alesia in conjunction with Vercingetorix. The Romans managed to repel both attacks. On 2 October, Vercassivellaunos led another raiding party against a weak spot in the Roman outer wall while Vercingetorix’s forces assaulted the inner wall with javelins, arrows, and slingshots simultaneously. Caesar poured reinforcements into the area while some of his infantry made futile attacks against Vercingetorix’s forces. With his lines on the verge of breaking, Caesar led his cavalry out and attacked Vercassivellaunos’ forces in the rear, causing the Gallic relief army to rout. On 3 October, Vercingetorix rode out to Caesar’s camp, where he surrendered himself and his army by laying his sword at Caesar’s feet, ending the siege. Casualties on both sides numbered 12,800 Romans and 40,000 Gauls.
What changed as a result?
The Battle of Alesia was a decisive Roman victory. Caesar spent the following year putting down minor revolts and formally annexed Gaul, adding it to Rome’s expanding empire. Vercingetorix was to remain a prisoner until 46 BCE when he was executed by strangulation in Rome. Gaul would become the most fruitful of Rome’s conquests, laying the foundations for the nation of modern France. However, Caesar’s success alarmed his enemies in the Roman Senate, who tried to divest him of his command. In 49 BCE, instead of relenting, Caesar crossed into Italy and started the Roman Civil Wars. Caesar would fight numerous battles against the forces of Pompey in Greece, North Africa, and Spain before declaring himself dictator for life. While his assassination in 44 BCE led to a further civil war between his successors, Caesar had permanently set the Roman Republic on the road to becoming a formal empire.
Bibliography
Caesar, Julius. Gallic War. Translated by Henry John Edwards. London, Loeb Classical Library, 1917.
Grant, R.G. 1001 Battles That Changed the Course of History. London, Cassell Illustrated, 2011.
Grant, R.G. Battle: A Visual Journey Through 5,000 Years of Combat. London, Dorling Kindersley, 2005.
Rodgers, Nigel. The History and Conquests of Ancient Rome. London, Hermes House, 2007.
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