What is so effective about cavalry charging infantry in the flank?

[Imperial Dave]

I read somewhere about animal behaviour that states that in a pack, individuality (and free will) suffers and "pack mentality" takes over especially under stress/threat conditions. Not sure if anyone did a study on humans in this way but it would make sense to say that we retain basic animal instincts that (autonomically) take over in certain circumstances.

[aligern]

That's what all that drill is about. When the cannonballs are flying at you and men are going down the familiar voice of sergeant or officer takes over from independent thought and keeps you standing or advancing.

No doubt the Romans had something similar and for mediaevals it would be more about following a lord's banner or the next man up the line in terms of social standing. There is a lot of substructure in Ancient units that we do not see, that keeps a man in place and trusting. What impresses me is the relatively few times that armies bolt and run. Mostly it takes hard fighting before an army collapses, even one whose position has been fatally compromised. That is why I plump for the effect of flank  attacks being a degradation of fighting ability through crushing together, not a big break-down in morale.

In fact, could the morale failure school cite many examples of flank attacks resulting in instant collapses?
Roy

[Patrick Waterson]

A worthy point.

Thucydides V.73 records that at the Battle of Mantinea (418 BC) the Spartan right and the Argive and Mantinean right were both victorious, but then the Spartans, instead of pursuing their defeated opponents, marched to attack the Argives and Mantineans.  These, "seeing ... the Spartans ... bearing down on them ... took to flight."

I am not sure we can count this as a 'proper' flank attack because the morale failure came about for reasons of feeling isolated rather than being hit in the flank per se.

Xenophon in the Hellenica (IV.2.21-22) describes the later stages of the Battle of the Nemea:

But the Lacedaemonians themselves overcame that part of the Athenians which they covered, and wheeling round with their overlapping wing killed many of them, and then, unscathed as they were, marched on with lines unbroken. They passed by the other four tribes of the Athenians before the latter had returned from the pursuit, so that none of these were killed except such as fell in the original encounter, at the hands of the Tegeans; [22] but the Lacedaemonians did come upon the Argives as they were returning from the pursuit, and when the first polemarch was about to attack them in front, it is said that some one shouted out to let their front ranks pass by. When this had been done, they struck them on their unprotected sides as they ran past, and killed many of them. The Lacedaemonians also attacked the Corinthians as they were returning. And, furthermore, they likewise came upon some of the Thebans returning from the pursuit, and killed a large number of them.

One may note how the Spartan use of an overlap to make a flank attack caused or at least contributed to their rapid success against the Athenians.  The Spartans were then able to take advantage of their ability to hit the right flanks of opponents returning from pursuit to fight a series of one-sided actions against the Theban and allied contingents.

Of note is the Battle of Amphipolis in Thucydides V.10:

Upon hearing this he [Cleon] went up to look, and having done so, being unwilling to venture upon the decisive step of a battle before his reinforcements came up, and fancying that he would have time to retire, bid the retreat be sounded and sent orders to the men to effect it by moving on the left wing in the direction of Eion, which was indeed the only way practicable. [4] This however not being quick enough for him, he joined the retreat in person and made the right wing wheel round, thus turning its unarmed side to the enemy.

[5] It was then that Brasidas seeing the Athenian force in motion and his opportunity come, said to the men with him and the rest, 'Those fellows will never stand before us, one can see that by the way their spears and heads are going. Troops which do as they do seldom stand a charge. Quick, some one, and open the gates I spoke of, and let us be out and at them with no fears for the result.' [6] Accordingly issuing out by the palisade gate and by the first in the long wall then existing, he ran at the top of his speed along the straight road, where the trophy now stands as you go by the steepest part of the hill, and fell upon and routed the centre of the Athenians, panic-stricken by their own disorder and astounded at his audacity.

[7] At the same moment Clearidas in execution of his orders issued out from the Thracian gates to support him, and also attacked the enemy. [8] The result was that the Athenians, suddenly and unexpectedly attacked on both sides, fell into confusion; and their left towards Eion, which had already got on some distance, at once broke and fled.

Brasidas hits the Athenian centre while it has its flank turned, with immediate results.  Clearidas hit the Athenian right, which also had its flank turned, but this held him off for a while and did not give way until surrounded (apart from Cleon, who ran at the beginning of the action).

Perhaps the key question in the above instances is: if these forces had instead been attacked in front, or entirely in front (i.e. no flank attack to muddy the waters), would they have collapsed?  The answer, based on their combat performance to that point, would seem to be no.  It would appear that in these cases at least being attacked in flank made a significant morale as well as material difference.

Not every flank attack will result in an immediate collapse: troops of good quality are more likely to withstand one, at least for a while, and seeing it coming allows countermeasures of a sort, including psychological (if, that is, the psychology holds up when the oncoming attack is perceived - as we have seen above, sometimes it did not).  At Pharsalus (Caesar, Civil War III.92-95), Pompey's cavalry collapsed when unexpectedly flanked by Caesar's 'surprise force' of six cohorts.  When these and Caesar's surviving cavalry flanked Pompey's infantry line, Pompey's high-quality First Legion, which was hit by the manoeuvre, held out for awhile and seems to have collapsed at around the time the rest of the line did so.

I trust this discussion will not polarise into one that maintains that either flank attacks have morale effects or they have physical effects; they have both, and if morale holds up the physical effects will be the more important while if morale does not hold up the physical effects will be icing on the cake.

[Mark G]

I'm pretty sure i recall sabins analysis of the punic wars putting the emphasis on the surprise effect of seeing a new threat to the flank.
If its telegraphed, that surprise is largely meaningless, and the fight continues.  The next big effect being physical rather than moral, caused by having to fight to two faces - which i think includes crowding as a logical consequence in many cases.

So that's mostly morale, but morale in anticipation of the problems expected if you stick around long enough to make it physical - in the same way that running from a stampede is morale based on knowing what happens if you don't.

[Imperial Dave]

I trust this discussion will not polarise into one that maintains that either flank attacks have morale effects or they have physical effects; they have both, and if morale holds up the physical effects will be the more important while if morale does not hold up the physical effects will be icing on the cake.

Completely agree with that Patrick. They go hand in hand. The question is which is the more devastating in what circumstances and why?

[Jim Webster]

Of course we could ask the question 'Is cavalry more effective than infantry when it comes to charging troops in the flank?'

If compaction and physical causes are the important ones, infantry can compact enemy infantry more than cavalry can because infantry can push the men in front so the compacting of the enemy would be even more noticeable
But you could imagine the speed and size of cavalry would give them a greater morale effect.

Jim

[Imperial Dave]

Of course we could ask the question 'Is cavalry more effective than infantry when it comes to charging troops in the flank?'

If compaction and physical causes are the important ones, infantry can compact enemy infantry more than cavalry can because infantry can push the men in front so the compacting of the enemy would be even more noticeable
But you could imagine the speed and size of cavalry would give them a greater morale effect.

Jim

Good question Jim 

I would propose that the cavalry flank charge might be the more physically disrupting initially because of the speed and momentum. If we accept that the cavalry physically crashes into the wall of men on the flank then the speed and mass of the horse and rider is higher individually than an infantryman. The speed thing also possibly sets up a ripple/shock wave to a greater extent with cavalry than infantry. After the initial impact, I would agree that the infantry would exert more compacting pressure as mass begins to tell with shoving etc