Ancient army numbers

[Paralus]

Yes, they planned to stick around (as in fact they did), living off the land. And seeing the Persians did not starve, they were probably able to gather suppies within Greece, something I doubt they could have done with an army of 300.000. But that's my guesswork.

Herodotus' numbers are vastly inflated. At 9.15 Herodotus says that Mardonius built a walled encampment some ten stades square. Wherefore to fit 300,000 plus cavalry mounts and everything else to go with the army? There is also no indication that, at Plataea, the Greeks were outflanked by massive Persian numbers. The Greek force was some 38,000 plus hoplites. Herodotus gives no role whatsoever to light Greek troops in the battle (which is not to say there were none though I doubt 35,000 helots to 5,000 Spartans) and it is unlikely that psiloi will have been used as infantry of the line. We are, then, forced to assume that Mardonius deployed his infantry something between 40-50 deep?

It is near certain that Mardonius had supply problems. Thucydides (6.33.5-6) puts the following words into the speech of Hermocrates as the Athenians sail against Syracuse:

Few indeed have been the large armaments, either Hellenic or barbarian, that have gone far from home and been successful. They cannot be more numerous than the people of the country and their neighbours, all of whom fear leagues together; and if they miscarry for want of supplies in a foreign land, to those against whom their plans were laid none the less they leave renown, although they may themselves have been the main cause of their own discomfort. Thus these very Athenians rose by the defeat of the Mede, in a great measure due to accidental causes...

The Greeks will have, eventually, fallen foul of each other had Mardonius waited. He did not wait though; rather he continued to seek a showdown and this is likely for reasons of failing supply once the fleet had departed.

Herodotus, himself, even seems embarrassed by some of his figures. Having told us that Xerxes sailed with 1,207 ships he realises that the 330 odd ships of the Greek fleet at Artemesium are plainly not in the fight. He thus prepares the way for the battle of Artemesium with a couple of timely correctives. Firstly he removes 200 Persian ships by sending them to destruction circumnavigating Euboeoa. Still with much leveling work to do, enter "storm soter" (Her.7.190-191)...

They say that at the very least no fewer than 400 ships were destroyed in this labor, along with innumerable men and abundant wealth [...] There was no counting how many grain-ships and other vessels were destroyed. The generals of the fleet were afraid that the Thessalians might attack them now that they had been defeated, so they built a high palisade out of the wreckage.

So the loss of 600 fighting ships brings the Greeks back into the realms of possibility!

Going back to the Greek v Persian issue - might it be possible that the irrigated farmlands of, say, Mesopotamia would have been far better for supporting large armies than the less cultivated lands of Greece? The Persians may have been able to field an army hundreds of thousands strong on their own territory, but would they take such a force on expedition into country less capable of supporting them? :-?

Command and control are still the problem. The Helleno-centric sources are very fond of the monstrous hordes that make up Persian armies. Xenophon, without the merest reflective thought, would have it that Artaxerxes had 900,000 at Cunaxa and should have had 1,200,000!

The Greek sources claim that Darius III marched 600,000 (plus supply animals) through the Bache Pass to Issus. Reduced to (a generous) four abreast and a metre of spacing through the mountains, this army will have stretched 150 kilometres (not counting supply animals. And this will have been similar wherever supply wagons and such demanded roads to move on.