Caesar’s victory at the Battle of Alesia, where the capacity of Roman military engineering allowed him to defeat a vast Gallic army that came to the aid of their leader Vercingetorix, ensured Roman domination of Gaul. Though, with all his fortifications, Caesar had to put up a tough fight.
Data from the Battle of Alesia
- Who is it: Gaius Julius Caesar (100-44 BC), with an army of 45,000 men, besieged an army of some 70,000 Gauls under the command of Vercingetorix of the Arverni (d. 46 BC) and faced a force that presumably numbered 250,000 warriors .
- As: Caesar drew on Roman expertise in siege operations, building lines of siege fortifications facing in and out, and Roman discipline to defeat threats from besieged and relief forces.
- Where: Alesia, about 50 km northwest of present-day Dijon (France).
- When: Late September/early October 52 BC
- Because: Caesar was trying to crush, once and for all, the threat of Vercingetorix against Roman rule.
- Result: The battle was the last effort of the Gauls against Caesar. The defeat of the charismatic Vercingetorix ended the Gauls’ ability to resist the Romans.
Background to the Battle of Alesia
In 59 BC Gaius Julius Caesar was elected consul in Rome. When he finished his consulship, he used his position and his political contacts to achieve his appointment as governor of Cisalpine and Transalpine Gaul and of Illyria. He became governor the following year and used the emigration of the Helvetii, and the unrest this caused among Rome’s Gallic allies, as a pretext to intervene militarily in Gaul.. Although it does not appear that Caesar’s initial intention was to conquer Gaul, his victory over the Helvetii may have given him the opportunity to consider this option. Over the next five years, Caesar successfully led a series of campaigns into Gaul, albeit sometimes narrowly, forcing many tribes to submit to him, at least temporarily. Moreover, Caesar also undertook campaigns across the Rhine, and twice invaded England..
Despite its success, there was a clear malaise in Gaul, which began to manifest itself at the end of 54 BC because of the poor harvest. Caesar was forced to disperse his soldiers in winter quarters throughout northeast Callia, demanding that the various tribes supply them with provisions.. This caused strong resentment which erupted into open rebellion. During the winter of 54/53 BC, a legion of 10 cohorts, with five additional cohorts, under the command of Quintus Titurius Sabinus and Lucius Arunculeyo Cota, was destroyed when the Romans were lured out of their fortified camp, ambushed, and annihilated. This was followed by an attack on a legion in their winter camp, which was under the command of Quintus Tullius Cicero (the brother of the famous orator Marcus Tullius Cicero). Cicero remained within his fortifications and, although his forces were hard pressed and suffered heavy losses, he was able to hold out until he was rescued. Caesar spent the rest of 53 BC raising additional forces, intimidating the Gallic tribes, and dealing with the Germans, both in campaigns across the Rhine and in repelling a major raid.
Map of the Battle of Alesia
The campaign and the armies
At the beginning of 52 BC, the Gauls planned a general rebellion aimed at driving out the Romans.. The revolt began at the beginning of the year with the massacre of the Roman citizens who lived in Cenabum, a city-state of the Camuto tribe. This signal inspired the Gauls, and a charismatic young nobleman from the Arverni, Vercingetorix, to assemble a coalition of tribes and field a significant army. The Gauls began by attacking the capital of the Boii, a tribe allied with Rome, but Caesar, who was in Italy, returned and forced the Gauls to retreat. Meanwhile, Caesar attacked several Gallic populations, in order to procure provisions. Vercingetorix realized that logistics was Caesar’s weak point, and so the Gauls adopted a Fabian strategy, in which they would avoid open combat against the Romans and would withdraw and defend their own fortified towns, in an attempt to deprive the Romans. Romans of much-needed provisions.
Meanwhile, Caesar continued his attacks on Gallic towns and tried to force a confrontation. He entered the territory of the Bituriges and attacked their main fortress, Avaricium. Vercingetorix tried to convince the Bituriges to abandon the town, but they were confident in their defenses. Although he camped outside the town, he was unable to prevent the Romans from besieging it. Caesar attacked the town while it was raining torrentially, when least expected, forcing Vercingetorix to retreat. Caesar took six legions and marched against the capital of the Arverni: Gergovia.
gergovia
This town was very important to Vercingetorix, who intended to defend it. When Caesar reached the town, which was situated on very broken ground, he occupied a hill and established a fortified camp there. He quickly took another hill, established a small camp there, and connected the two with a pair of parallel ditches. César observed a small hill that gave access to the population and that was practically defenseless. He ordered some of his soldiers to start a diversionary maneuver and launched an attack on the hill, which he took with relative ease.. The soldiers, however, continued their advance to the town walls, either under Caesar’s orders or, as he tells it, simply excited by their success; They met strong resistance there and were repulsed with heavy losses, especially among the centurions. At this point, Caesar was forced to lift the siege and withdraw from Gergovia.
Gergovia’s defeat was a heavy blow for Caesar and an advantage for Vercingetorix. The defeat caused some of Caesar’s oldest Gallic allies to go over to the enemy.
retreat to alesia
Vercingetorix began to recruit additional troops for the rebellion and, using a large cavalry force, began to intercept Roman efforts to gather supplies. Caesar, to compensate for the losses caused by the defections, especially in his cavalry, recruited German cavalry and light infantry to back it up. Realizing that his forces could not meet Caesar’s in the open field, Vercingetorix decided to withdraw to the fortified city of Alesia, hoping to repeat the defeat of the Romans at Gergovia.. Caesar followed him and prepared to besiege the city.
roman legionnaires
Provisions
Vercingetorix and his army built a fortified camp adjacent to Alesia. defended by a moat and an embankment 1.8 m high. Caesar concluded that Alesia and the Gallic camp were too strong to be assaulted, and decided instead to surround and blockade the city.. He began by building seven fortified camps supported by 23 redoubts to defend key positions. While these fortifications were being built, Vercingetorix sent his cavalry to hinder the Romans. A cavalry battle ensued, in which the Gauls were severely beaten by Caesar’s cavalry, especially by the Germans.. Vercingetorix then decided that his cavalry would attempt a breakout during the night. Gallic horsemen slipped through the gaps in the Roman ranks and returned to their communities to raise a fresh army to succor the besieged.
With the Gallic cavalry fleeing and a relief army likely appearing, Caesar decided to increase his siege constructions.
First, he built a 6m moat, with perpendicular sides, to prevent the Alesian Gauls from hindering the construction of more complete fortifications. After this pit, two
additional moats, and the interior was filled with water. After these, a 3.6 m high embankment was erected with the earth extracted from the ditches. This was crowned with a palisade and protected by sharpened stakes. To further reinforce the embankment, regularly spaced towers were arranged along it. The length of these constructions was almost 16 km.
Vercingetorix, during the construction of the fortifications, made a series of important and coordinated sorties out of the city, which interfered with the construction and made it difficult for Caesar to send supply parties. This one, he added three lines of traps. The first consisted of five rows of tree trunks and strong sharp branches, placed in trenches; In front of these were 90 cm deep holes arranged in the shape of a chessboard, with sharpened stakes inside; and, ahead, were strewn with iron hooks attached to wooden blocks.
To defend against the relief army, a similar set of fortifications was built, 28 km long, facing outwards, with plenty of space in between for Caesar to move his troops. The Gauls inside Alesia recognized that supplies would be insufficient, so they sent those who could not fight out of the city. The non-combatants made their way to the Roman lines, but were repulsed by Caesar, and so were left waiting to starve in no man’s land.
ballista
the battle of alesia
The Battle of Alesia began when the relief forces arrived and, having camped 1.5 km from the Roman lines, they sent their cavalry onto a 5 km wide plain. The Gallic horsemen were interspersed with archers and light infantry, while the main body of infantry formed up to watch over their cavalry, which was the elite of the army.
Confrontation outside the fortifications
When the Alesian Gauls saw the cavalry lined up for battle, they stormed out of the city and filled the Roman moats with sashes, in preparation for a sortie. Caesar responded by manning the ramparts with all his infantry, making sure that all men knew where he stood, and sending his allied Gallic and German horsemen to engage the enemy cavalry. The action of the cavalry was hotly contested, as the Gallic horsemen benefited from the support of the infantry, which the Romans did not expect, but finally the Romans got the best of it, when Caesar concentrated his German cavalry in a single point and disbanded. to the Gallic cavalry. The latter fled, leaving his supporting infantry to be slaughtered. The Gauls inside the siege fortifications lost hope and withdrew back to Alesia.
Assault on the Roman fortification
The Gauls in the relief force spent the next day preparing the materials needed for a major assault, including ladders, assault hooks, and sashes. At midnight, they advanced silently, and when…