Caesar Tightens the Noose at Alesia
Caesar laid siege to the city of Alesia, but according to Plutarch, who wrote about the event in the early part of the second century AD, the Roman commander was expected to fail in his attempt. Plutarch claimed there were 170,000 men inside Alesia and its high walls made it almost impossible for a small Roman army to take. Furthermore, an estimated 300,000 Gallic warriors arrived, so the Romans were trapped and were now under siege themselves. Caesar’s figures are very different. He wrote that there were 80,000 men in Alesia and 240,000 troops arriving as reinforcements.
The Romans seemed doomed but Caesar, as usual, had different ideas. There is a school of thought that Vercingetorix didn’t expect the Romans to follow him to the city, but once again, he miscalculated. The politics of Rome meant that Caesar could not return home without a decisive victory. To do so would leave him under threat from enemies within the city. He knew that Alesia was a chance to end the war decisively and he wasn’t passing up the opportunity.
The Siege of Alesia
Once Caesar arrived at the city, he knew that the best option was to starve out the inhabitants. Alesia was a fortified settlement on Mont-Auxois which was over 400 meters high; there were also different rivers on two sides. Also, Vercingetorix had ordered the construction of a ditch and six-foot wall where the hill faced east. Caesar had fewer than 50,000 men and decided to encircle the hill with siegeworks to encircle the enemy and force a surrender.
The circumvallation was about 16 kilometers long with 24 towers. Once completed, there would be no way for the Gauls to flee but before the fortifications were finished, Vercingetorix was able to sneak troops past the Romans, and they rode off to call for reinforcements. The inhabitants of Alesia had around one month’s worth of provisions left according to the calculations of the Gallic leader.
Caesar was informed of the news by captives and deserters and realized that he had to create a countermeasure immediately. He ordered the creation of a trench that was 20 feet deep with perpendicular sides. Next, he built all other works some 400 feet from that trench. In between these two points, he ordered the digging of two more trenches; each of which was 15 feet in length and depth with the inner one filled with water.
Caesar was far from finished as he ordered a 12-foot rampart, a wall with a parapet and huge stakes sticking out which was surrounded by turrets situated some 80 feet apart. By the time the Romans had finished, they had an array of traps just waiting for blundering enemies to wander into. Inside Alesia, the inhabitants sent out their women and children in the hope that Caesar’s army would feed them. He knew this would ruin his plans, so he sent them back without food. Meanwhile, a massive number of Gallic reinforcements had arrived and set up camp just one mile away from the Romans. It was made or break time for the legendary commander.