Battle of Gergovia

As with much of the conflict between Rome and Gaul in the first century BCE, information about this battle comes principally from Julius Caesar's Commentaries on the Gallic War. There are no surviving Gallic accounts.

Vercingetorix had earlier been expelled from Gergovia, the capital of the Arverni, by its government.[3] In winter 53 BC, while Caesar was gathering his forces for a strike against the Gauls, Vercingetorix came back to Gergovia but was now supported by the Arverni, his people.[4] Caesar states that he was left with a difficult decision. He could have kept his forces safe over the winter, but would have showed Roman weakness in defending its allies the Aedui and thus losing their support. However, he chose to bring Vercingetorix to open battle but risked running out of supplies.[5]

Leaving two legions and all of his baggage train behind in Agedincum, Caesar led the remaining legions to Gergovia. His sieges of Vellaunodunum, Genabum, and Noviodunum en route caused Vercingetorix to march to meet Caesar in open battle at Noviodunum, which Caesar won.[6] Caesar then besieged and captured Avaricum and resupplied there. After resting his forces at Avaricum, he sent his top legate, Titus Labienus, with four legions north; this to keep the northern Gauls from interfering with his campaign against the Arverni.

Caesar then set out in the direction of Gergovia, which Vercingetorix was probably able to guess easily once he had remarked his direction. The heights of Gergovia stand twelve hundred feet above the plain that they overlook. It is a plateau that is a mile and a half long by a third of a mile wide. It was an advantageous place to hold, as there was only one way in, and a small body of troops could hold the entrance to the place.[7]

Vercingetorix therefore crossed the powerful river Elave (now Allier, a tributary to the Loire at Nevers), and started marching up and down the bank, mirroring Caesar's movements and destroying all the bridges to keep him from crossing, the purpose presumably being to destroy part of his force as he attempted to cross. Realizing Vercingetorix's plan, Caesar resolved to trick him and cross under his very nose.[8]

Caesar one night camped near the town of Varennes-sur-Allier,[8] where there had previously been a bridge before Vercingetorix had destroyed it. That night, he divided his force into two parts, one part being two thirds of the force, the other being one third of the force. He ordered the larger force to march in six corps as if it were really the full army of six legions.[8] He then ordered it to continue its march south. Vercingetorix, duped, took the bait and followed this part of the force.

Caesar, with the two legions still at Varennes, speedily rebuilt the bridge that had been present there. He then sent for the other force, which the next day stole a march on Vercingetorix and completed a junction with the original force, and crossed the rebuilt bridge.[8] Realizing that he had been duped, Vercingetorix set out south to beat Caesar to Gergovia.

Five days later Caesar reached Gergovia, the first march being short because most of the troops were tired after marching up the river and back and the last march because the legions arrived at the town.[9] Realizing that its mountainous location made a frontal assault risky, he decided to rely on his superior siege tactics. Upon arriving, Caesar discovered that there was a small hill that the Gauls held that was essential to their holding Gergovia itself. From there, they were able to provide water, grain, and forage.

Caesar took this in a night raid and swiftly stationed two legions there. He then linked it to his main camp by digging a double trench, twelve feet wide, with a parapet. The result was a barrier that kept the Gauls from their supplies, which they needed desperately.[10] They were forced to subsist on the meager stream that supplied water to Gergovia itself.[10]

The Aedui leaders during the course of the siege had been corrupted with both gold and misinformation by emissaries of Vercingetorix.[11] Caesar had agreed with the Aedui that 10,000 men would protect his line of supplies. Vercingetorix convinced the chief, Convictolitavis, who had been made chief of the tribe by Caesar, to order the same men to join him upon their arrival at the oppidum.[11] They attacked the Romans who were accompanying their supply train, leaving Caesar in an embarrassing position.

His rations threatened, Caesar took four legions from the siege, surrounded the Aedui army, and defeated it.[11] The pro-Roman faction retook control of the Aedui leadership, and Caesar returned to Gergovia with 10,000 pro-Roman Aedui horsemen. The two legions that he had left to continue the siege had been hard-pressed to keep Vercingetorix's much larger force at bay.[11]

Caesar realized that his siege would fail unless he could get Vercingetorix off the high ground. He used one legion as a decoy while the rest moved onto better ground, capturing three Gallic camps in the process. He then ordered a general retreat to lure Vercingetorix off the high ground. However, the order was not heard by most of Caesar's force. Instead, spurred on by the ease with which they captured the camps, they pressed on toward the town and mounted a direct assault on it. The Aedui arrived at that moment, but the Romans mistook them for enemies at first, and Caesar had to make order in his lines.

The noise of the assault alerted Vercingetorix, who arrived and saw the Roman and Aedui just beneath the walls of Gergovia. Vercingetorix then led a cavalry charge that crushed the Roman lines. Then the warriors left their horses and joined the infantry in their fight against the Romans, who soon had suffered heavy casualties.

Given his losses, Caesar ordered a retreat. In the wake of the battle, Caesar lifted his siege and fled the Arverni lands northeastwards in the direction of Aedui territory. Vercingetorix pursued Caesar's army, intent on destroying it. Meanwhile, Labienus had finished his campaign in the north and marched south. After linking up with Labienus' corps, Caesar marched his united army south and the war continued.

• Gergovie Monument

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