The Number Problem in the Persian Wars 480-479 BCE

[CaesarAugustus]

Marco, I am looking at numbers of soldiers because nobody counted everyone, so if I tried to compare numbers of heads I would be comparing one calculation to another calculation.  So Herodotus claims that there were many noncombatants in addition to his 1,800,000 soldiers, 1,207 triremes, and 3,000 smaller ships, but he does not claim to know how many there were, he shows his reader how he estimates them (and because we can read cuneiform, we know his assumptions were wrong: Mesopotamian armies did not have a servant for each soldier, they had central groups of cooks, leatherworkers, and so on).  The same for the size of the Greek army at Plataea: he only claims to know the number of hoplites, Helots, and unarmed Thespians, he says he is estimating the rest.

Whereas if we compare numbers of soldiers, we can start from numbers in sources (although who gets counted is still an issue). 

Its important to compare numbers for the same thing, because generally the number of soldiers in a war is greater than the number present in any one army, and the number who start a campaign is always greater than the number present in the main army months later.  People often use the first kind of number to argue that the second kind of number could have been higher than we ever see.

Spend some time looking through ancient sources in different languages for armies of more than 100,000 soldiers.  I think you will find that there are fewer than you think, and they are in the Old Testament, a few Late Antique writers who knew the Old Testament, stories about barbarian invaders who the writer never saw, and the Roman civil wars which ended with Augustus becoming emperor.

Dear friend,

I think that we have already confuted the main objection, that was related to the "difficulty" to feed a massive army. We have seen that there is no reason for which we should think that a massive army should rely on what it is possible to find on the spot, any army worthy of the name would rely on logistics. Obviously, more or less efficient, but surely it would not rely exclusively on what it found on site.

We have also seen that it is possible to find several different references to big armies, even before AD. I would think to Mark Anthony's army in Parthia. But also to the Battle of Arausio, or to the Battle of Alesia. We can discuss until the end of the time, but it is a fact that we have these references and and they are consistent in their scenario.

Now, what we miss to have a coherent scenario for the Persian invasion in Greece? An estimate of the Greek forces that is able to contextualize the numbers.
Do we have some data? Luckily yes. We know that, thanks to silver mine found, Athens had been able to deploy a significant number of triremes. Maybe not the 200, but according to Herodotus 180 just for Salamina. According to Plutarch, the initial desiderata was to create a fleet of 200 triremes. Now, what does it means? That just Athens was able to have a naval force of around 40000 men. Just for the naval force. We perfectly know that there was not just Athens, and that there was not just the naval force.
And our scenario is not complete. We have seen that Greek forces were able to deploy tens of thousands of men but despite this, they abandoned and evacuated, practically without fighting, one of their principal capitals... the same Athens, that same city that was able to deploy around 40000 men just for the fleet. There is only one explanation for this, that the Persian army was so huge, so massive, that the evacuation was the one of the few cards available.

Now, the scenario is complete. We have seen that it is practicable, and it is coherent not only from a Persian point of view, but it is consistent with the reaction that we can read in the Greek army. A Persian army of 40000 men is absolutely inconsistent with what happened, apart from being denied by literary sources.