The Makedonian phalanx -- why such depth?

[Paralus]

Okay, question then from you guys. It is often said that Philip II "learned" a lot as a Theban hostage and applied this knowledge to his own phalanx many years later.

What is generally thought to be put down to Philip’s time at Thebes are:

• The elite infantry (the pezhetairoi) unit - "professionally" trained

• The application of that unit in echeloned advance

• The combination of cavalry and infantry at a point exposed by the echeloned advance

In summary, the directed application of force at a single point to achieve a breakthrough rather than the Greek crash of hoplites in a push and shove match. Bardyllis found out the effectiveness of this tactic – to his immense cost – when he lost 7,000 Illyrians to it at Philip’s hands. This likely also saw him deepen his phalanx (ten then 16 deep) when, as the sources make plain, he “invented” it (for Macedon).

What sometimes goes unremarked is the same tactics in “international relations”. Epaminondas wrote chapter and verse on the neutering of Spartan hegemonic ambitions during his “visits” after Leuktra. Philip showed this was not lost on him when he similarly emasculated Sparta’s ability to project any force internationally with his apportioning off of Spartan territories to his allies after Chaeronaea. Henceforth Sparta was reduced to an unhealthy fixation with Magalopolis for it could do little without the recovery of Messenia.