One notable difference between Caesar’s and Plutarch’s descriptions of the siege of Alesia is how the authors list the numbers of the Gauls. Specifically, Plutarch estimates the strength of the army coming to the aid of the besieged city as three hundred thousand and the besieged army as one hundred and seventy thousand (Plutarch, The Life of Julius Caesar, 27.3-4). Caesar estimates the strength of the besieged army as “eighty thousand chosen men” and that of the relieving army as eight hundred cavalries and a quarter of a million infantry (Caesar, Gallic War, 71, 76). This is also a huger exaggeration, but the number is smaller and, thus, more reliable.
Another contrast between the two sources is Plutarch’s account of the battle is much more schematic. If the ancient historian is to be believed, the Roman forces protecting the inner wall against Alesia were not even aware of how the battle on the outer wall went until they saw the spoils of war (Plutarch, The Life of Julius Caesar, 27.6). However, Caesar mentions regularly moving troops between the sectors. For example, Marcus Antonius and Gaius Trebonius “withdrew troops from forts farther away, and sent them up to bring assistance” (Caesar, Gallic War, 81). It makes sense because, when hard-pressed, Caesar would most likely take troops from the less threatened sectors to reinforce the more threatened ones. Therefore, many troops would have at least some idea of how the battle was progressing in different sectors. Considering this, Caesar’s account is also more reliable tactically, and Plutarch uses the idea of sudden and unforeseen victory to make things more dramatic.
Still, one should remember that the Gallic War was as much a work of self-glorification as it was a historical treatise. Caesar draws specific attention to how he, instantly recognized by his cloak, personally inspired soldiers at the key points of the battle (Caesar, Gallic War, 88). In contrast, Plutarch only speaks of “deeds of skill and daring” in general terms and does not provide anecdotes of Caesar’s personal valor (Plutarch, The Life of Julius Caesar, 27.5). Since Caesar had every reason to portray himself in the best possible light, he is likely less truthful in this regard. Thus, Caesar’s account is more reliable in a tactical sense and slightly less exaggerated when it comes to numbers, but Plutarch is probably more reliable in terms of Caesar’s personal participation in action.
Bibliography
Caesar. “The Gallic War.” Adobe PDF File.
Plutarch. “The Life of Julius Caesar.” Adobe PDF File.