Did the Gallic army besieged in Alesia conduct itself well when expecting relief?

Question

During a Gallic revolution against Rome, a Gallic army of some 80,000 men took shelter in the fortress town of Alesia, where they were besieged by some 50,000 Romans under Julius Caesar. (His army may also have included some non-combatants such as builders, wagon drivers, etc. that brought the total to 60,000 or 70,000.) Thus the Roman army was numerically inferior but qualitatively superior, having beaten the Gauls in a pitched battle at Gergovia.

Vercingetorix managed to send some cavalry through the Roman lines to seek help, (which was forthcoming), but otherwise did little to arrest the progress of the siege. Because of that fact, the Romans were able to complete a line of "circumvallation" fortifications between their lines and Alesia, and then another set of lines of "contravallation" between the OUTSIDE of their armies and the relieving forces.

http://en.wikipedia.org/wiki/Investment_%28military%29

One line of defense against the "mining" of a besieged city is "countermining." In this case, it would have consisted of constructing one or more trenches from Alesia perpendicular to the "circumvallation" fortifications. This would have allowed the Gauls to approach the Roman lines for hand-to-hand combat under the protection of their own trenches.

Would it have made sense for the Gauls to engage in an all-out war of attrition to disrupt the circumvallation process? They were no match for the Romans in open field, but might they have been more successful in a confined area, particularly in say, night attacks?

The purpose would NOT to break out, but to weaken the Romans vis a vis the relieving Gallic forces (of over 100,000), perhaps by trading casualties at a 2 to 1 ratio (40,000 Gauls for 20,000 Romans). And if they could set back the Romans' timetable so they could build only the inner wall but not the outer wall, might it have been worth it?

Given that the besieged Gauls were short of food other implications were 1) battlefield casualties would have meant fewer mouths to feed, and 2) the opportunity to capture some supplies from the Romans (most soldiers carried some of their own food).

Or was Vercingetorix's "better" option to wait for a battle on the "last day" before his besieged army ran out of food (as he did), even though he lost?

Answer 1

It seems to me that most of the things you suggest Vercingetorix might have done is what he actually did. They did try to stop the circumvallation, but failed to make a noticeable impact. Once help arrived they tried to attack from both sides at once, also at night, which was close to succeeding.

Of course, everything we know about this siege comes from Julias Caesar himself, and as this almost successful attack was finally countered to a large part through Caesar's personal bravery, he might have takes some license with actual facts.... :-)

You can't exactly say that Vercingetorix tried a all out war of attrition, but it seems like a besieged city that are low on resources are doomed to lose any war attrition per definition.

See the Wikipedia article about the Battle of Alesia and "De Bello Gallico" and Other Commentaries by Julius Caesar.

Answer 2

Some comments from others (in addition to the answer) shed light on why Vercingetorix failed. One was that Caesar was a "genius." It is is precisely for this reason that Vercingetorix should have used attrition tactics. Caesar will outmaneuver your army in open field. Your best chance of winning is to use your superior numbers to engage in "knife fights."

The same person pointed out that it was not a "rebellion." True enough, from the Gallic point of view. But the Romans regarded Gaul as their province, and treated Vercingetorix like a "rebel." ("Gallia est in tre partes divida.")

Ulysses S. Grant waged a successful war of attrition because he knew 1) he was fighting the "great" Robert E. Lee, and 2) he was fighting "slavery." Does Grant's use of attrition tactic support his reputation as a general?

(The Gauls had no idea that they would be slaves of the Romans for 500 years; they treated it as another "tribal" war.) Hence, they appeared to lack the "do or die" mentality need to fight a war of attrition.

Then, we have the modern example of Stalingrad. At that battle, the Russians deliberately moved their trenches as close as possible to the Germans' to nullify the latter's initial superiority in "heavy weapons," tanks and planes. They would stage nightly grenade attacks to exhaust the Germans, and send "raiders" behind the German lines to steal food and water or at least "spoil" it for the Germans. German commanders initially criticized the Russians for "wasting lives" (more Russians than Germans were "caught" in these fights), but later admitted that these attacks exhausted and demoralized their remaining troops. Of course, the Russians knew that "slavery" (or worse) was in store for them if they didn't win.

One clear thing that Vercingtorix probably should have done was to "countermine," that is, dig one or more trenches from the city to the Roman lines. He probably feared Roman retaliation, but should have welcomed it, because his men could have fought the enemy on far more even terms in the trenches than in the open field at any given time. This would also have had two important effects on the "last day" of the battle:

1) The besieged soldiers could start their "breakout" from positions already in place, rather than having to approach the Roman lines without the protection of trenches.

2) They would have signalled the relieving force the best place to break in. As it were, the relieving force approached from the northwest, their "natural" direction, which also featured the best defensive terrain (for the Romans). Which is a major reason the Gauls lost.