The Makedonian phalanx -- why such depth?

[Paullus Scipio]

Paralus/Michael wrote:

Before we go any further, I should not that I don’t – inherently – find anything wrong with files filling space to “close up”. I just don’t think there is enough evidence to hang my gonads on it.

...For the earlier period, I believe there is sufficient evidence, particularly in Xenophon, as to leave little doubt....

I disagree with the notion expressed in the last sentence. Polybios makes great play of the phalanx’s vulnerabilities and drawbacks and seeks to explain the Greek loss to Rome. Put simply, he describes its charge as irresistible as long as it maintains integrity. That, he avers, is impossible on anything other than cleared level ground. Off such ground it is want to fall apart. As well, he states it is only good for the charge and only in the one direction; it cannot manoeuvrer due to its pikes nor cannot it defend itself if breached in any fashion. It cannot disengage and face about and it most certainly cannot cope with creeks or rivers......Despite Polybios’ derision of Kallisthenes, and unless the historical tradition which has come down to us is worth nought, Alexander’s phalanx demonstrably coped with all of the above. If Polybios is to be believed, the Hellenistic phalanxes of Philip V and Perseus were nothing near as skilled or flexible as that which Philip II bequeathed Alexander.

Well, the manuals certainly represent the epitome of the full evolution of Greek/Hellenistic drill. As to what the Macedonian style phalanx, especially the later ones, could and couldn't cope with depended on too many factors, not just it's drill standards. However, at Sellasia, the Macedonian phalanx ascended mountains, before, on their right tackling a Spartan fortified camp, and on their left ascending a mountain, marching over the crest and tackling the Spartan phalanx in a fairly narrow curved saddle....all of which gives the lie to the 'flat ground only' idea, or that the later Macedonian phalanx was necessarily worse than it's Alexandrian forebears. These are demonstrably incorrect cliches. Polybius' remarks are generalisations, and should be recognised as such....though I would agree that clearly what he says is generally true.

The “peltasts” referred to are part of the phalanx and not a screen – both are ordered to close up to the right. The light infantry, from memory, are engaged below and that which is not is deployed on the phalanx’s wings rather than in front.

Sorry, my usage of the term was careless - you are quite correct that 'Peltasts' was the elite unit of the phalanx, and to avoid confusion I should have used another term for the Light/medium troops who were mercenary and Thureos armed ( but who are referred to by the old term 'peltasts' in the manuals). Technically 'mistophoroi' or 'thureophoroi' is probably better.....
My memory was also incorrect regarding their deployment. Earlier, a skirmish between them and Macedonian cavalry, and the Roman velites and their supporting cavalry had gradually built into a battle which swayed to and fro up and down the slopes of the ridge.Ultimately, Philip received them ( his advanced force of mecenary thureophoroi and cavalry and light missile troops) into his ranks ( i.e. the Phalanx in open order) and ordered them to deploy to the right wing. Only then did Philip order the Peltasts and Phalanx to double their depth and close up to their right. When this manouevre was complete the Romans moving up the slope were quite close, and Philip ordered his men to lower their pikes and charge. The Roman light troops also withdrew through the maniples, and so the Phalanx crashed into the Legions. Given the downhill charge and their compactness into a sort of column etc it is hardly surprising that the Phalanx prevailed.