The Gauls found a weak point in Caesar’s defences.
Sketch of the Battle of Alesia, drawn by Muriel Gottrop (Creative Commons Attribution-Share Alike 1.0 Generic license photo)
The ground around Alesia wasn’t all flat. One of the hills was so large that Caesar’s soldiers could not encircle it and they had had to build their wall below it, thus giving the enemy the advantage of higher ground. The Gallic general became convinced that a massive attack coming down that hill would break through the Roman defences. He brought together his best 60,000 warriors and marched them in secret during the night. They camped behind the hill and rested the next morning. At noon they formed and, with a thunderous war cry, rushed down the hill.
Their cry was once again the signal to Vercingetorix to charge out of Alesia and begin his own attack on Caesar’s inner wall.
Suddenly there was fierce fighting everywhere along the walls. The most important moment of the Battle of Alesia had come. Caesar said both sides knew everything hung in the balance and that they had to exert themselves to the utmost because defeat meant death or slavery. Unless they broke through the Roman defences the Gauls must despair of saving themselves, and unless the Romans held their positions they would be annihilated to a man.
The fighting at the wall below the hill was the most intense. The Gauls were succeeding. They covered Caesar’s traps with earth and filled in his ditches. For the first time, they came up to his wall. Forming a “tortoise” (a unit of men holding their shields together above them in tight formation), they began tearing down the wall with grappling hooks. The Roman defenders were soon out of ammunition and strength.
Replica of the fortifications used in the siege of Alesia, Archéodrome de Beaune, Merceuil, Bourgogne, FRANCE (Creative Commons Attribution-Share Alike 2.5 Generic license photo by Christophe.Finot)
Caesar saw what was happening from a tower on the wall. He ordered his captain Labienus to take six cohorts (3600 men) and hurry to help their wavering comrades below the hill. “If you can’t hold the line, fall back a little, regroup and counterattack,” he told him. “But only as a last expediency.”
Another section of the outer wall was in trouble too. On the plain there were traps in front of the wall but other sections were protected by cliffs or steep ground. One large contingent of Gauls now climbed one of those steep ascents and stormed the wall where they knew the defenders were few. They too began tearing down the wall. The situation became critical. Caesar sent his legate Brutus with a few cohorts and then Fabius with more. Finally he went there in person to encourage the soldiers. Caesar always wore his imperator’s red robe and went barehead, so he was easily distinguishable. Just seeing him and knowing he was watching them made his soldiers fight harder. And he spoke to them too, encouraging them, calling them by name. “Ah, there’s Quintus Valerius fighting like the good soldier he is!” and “Come on, Gaius Sempronius, give ‘em hell!” and “I’ll tell your son about this one, Marcus Bibilus!”
When he thought things were under control there, he looked back to the fighting at the foot of the hill and he didn’t like what he saw. Labienus, with all his cohorts, wasn’t holding off the enemy.
Caesar decided to put into effect a last contingency plan of his own. It won him the battle.
He ordered his remaining reserve troops and half the German cavalry to line up behind him. The other half of the cavalry he told to ride out as fast as they could, steal behind the hill where the Gauls had hidden that morning, and charge them from the rear.
Then he broke out in front of the wall and engaged the enemy head-on in hand-to-hand combat. It was there and then or never—the crisis had come.
When the Gauls saw that the Romans had come out to fight, they were fired with hope and sent up a great battle cry. Now they would finally get their hands on their country’s invaders. “Their shouting was answered by a shout from our own walls and ramparts,” says Caesar. His troops were fired too. He had taken them from his reserve force and they were fresh and glad to be going into combat finally. They formed in the disciplined Roman way, threw their spears and then fought with their swords.
The Gauls, who Caesar says were as brave individually as Roman soldiers, fought desperately, though against Roman organized fighting they were always at a disadvantage. Suddenly they heard shouting behind them. It was Caesar’s cavalry! They panicked and turned tail; and a great slaughter ensued as the cavalry and Caesar’s soldiers ran them down. “Had they not been so exhausted from the fighting, our men would have killed every last one of them,” Caesar wrote. The best Gallic leaders were killed or captured. The few men who escaped ran home.
Caesar called for unconditional surrender. “Have all the ringleaders brought before me,” he said.
Vercingetorix throws down his arms at the feet of Julius Caesar by Lionel-Noel Royer (public domain photo)
Read Caesar’s Great Victory for Plutarch’s colorful account of Vercingetorix’s surrender. Caesar kept him for his triumph parade back in Rome but gave the other prisoners to his soldiers, one to each, as booty.
The Gauls were never again able to unite against Rome. Caesar’s own memoirs stop here—the rest of his Commentaries was finished by a captain of his, telling of a few more revolts before Gaul was finally “pacified”.