The Makedonian phalanx -- why such depth?

[Paullus Scipio]

Thanks for the exact translation! It would appear that Arrian believed the three Macedonians stood at the front, then. I still have a few lingering doubts, though, mainly because 12 would be an unusually deep formation for archers to fight in ( throughout most of history, particularly the Middle Ages, archers generally fought 4-6 ranks deep.) Even with this 'lacuna' in Alexander's 'new-fangled ' phalanx, we should remember that a 'dimoirites' etc existed in the 'normal' Macedonian phalanx of PtolemyI, and I don't think one would suppose that an ordinary second-ranker received double pay, so he at least is more likely to have been a 'half-file leader'. As I remarked earlier, it really doesn't matter where the 'dimoirites' stood Alexander's one -off phalanx, it suffices that the rank existed. That it meant someone who held a rank/position, and meant more than simply an ordinary soldier receiving twice as much pay, is certain, for the Mate of a ship (second in command) was also called Dimoirites.

Nor, Paul, was this formation to be used against horse archers; where it would have been clumsy and quite useless;

Since it never saw action, I don't see how you can arrive at that conclusion. Foot archers generally outrange Horse archers, regrdless of relative bow-power, because of aiming difficulties, and a Persian line of spearmen behind mantlets, backed by archers was very effective indeed against them. Arrian himself, drawing up a Roman line against Alans sought to defeat them in exactly this way - a line of spears/sharp pointy things to fend off the horsemen, backed by missile troops. Far from being 'useless' such a formation was optimal against horse archers.

The intended enemy were the Arabs also light horse but javelin armed and therefore forced to come into close enough quarters to make the missileman filling effective. Like Bosworth, however, I doubt how well it would have performed.

Interesting.What is the evidence that Arab armies consisted of javelin armed light horse at this time? And if the Foot archers outranged both horse archers and mounted javelinmen alike, what is the difference? Further, what makes Bosworth think he knows better than Alexander how to form up these troops, or how effective they would have been?

I believe these were confused by one source with the Persians brought by Peucestas, who were untrained, probably because they were both 30,000 strong.

If the Persians brought by Peucestas were archers, then they were hardly 'untrained' ! It takes long training to produce an archer, again as I have pointed out earlier.

at the time of Alexander ‘dimoiretes ‘ meant double pay man and nothing more that later this was the pay scale of a half-file leader is irrelevant. The best argument for half-file leaders is the eight deep formation at Issos. But that does presuppose sixteen to be a full file.

I don't see any evidence for concluding 'nothing more' as I set out above - the word also refers to the second-in-command of a ship, nor is the later evidence 'irrelevant' since the successors phalanxes evolved from Alexander's, and the earlier Hoplite phalanx, which also contained half-file leaders ( see Xenophon) That 16 was the depth of the Macedonian phalanx ( in 'normal' order, I would aver :wink: ) can hardly be doubted , for a phalanx 32 deep was called 'double phalanx'.
I don't maintain my hypothesis is conclusive - there is too little evidence for that, and what we have is of a patchy nature. What I do say is that all the evidence is consistent with the hypothesis, and that it is likely that throughout it's history, at least from Xenophon's time and probably earlier, the evidence suggests that the Phalanx manouevred in files in open order, and that just before contact with the enemy closed up into 'close order' to fight. I have yet to see another explanation which takes account of all the evidence and factors.