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

[Justin Swanton]

The doubts raised about Companions charging formed hoplites from the front has gone hand-in-hand with the notion that they would have no problem charging them in the flank.

On the face of it though there is a problem. It is generally agreed that if a cavalryman comes to a halt in the middle of a formation of hostile infantry he will very soon be a dead cavalryman. Charging the flank however seems to imply penetrating the infantry line from the side, which means having to get, not through 8 or 16 ranks of men, but hundreds of files. In other words, a horse is far more likely to come to a halt penetrating an infantry line from the flank than from the front. What then is so advantageous about charging infantry in the flank?

Add to that the fact that only about half a dozen files of the cavalry force will actually be able to contact the infantry line on its edge; the rest just gallop into space in front of or behind the infantry.

Just saying the infantry are shocked/demoralised and subsequently panic doesn't cut it. They must be shocked/demoralised for a reason. An earlier thread examined how infantry, by overlapping around to the rear of another infantry line, could put their opponents under pressure, deny them recoil and fighting space, and finally crack their will to fight. A cavalry charge however is a different story - the cavalry must keep moving: hitting home then retiring to hit home again. Unless they are cataphracts they cannot afford to remain in contact with the infantry and put them under pressure.

So what is so effective about a flank charge?

[Jim Webster]

Because when you think about it, the enemy that are behind your flank are almost certainly across your rear. The morale effect of that is probably the most important thing.
I think when you talk about ranks, yes obviously they do have an impact, but the willingness to fight is more important

Jim

[Imperial Dave]

There is the morale effect for definite but also, and I am happy to be corrected, a side impact may mean there is not enough time to reorganise the infantry and "brace for impact"?

[Justin Swanton]

There is the morale effect for definite but also, and I am happy to be corrected, a side impact may mean there is not enough time to reorganise the infantry and "brace for impact"?

All the infantry need to do to prepare for a flank charge is turn 90 degrees to face the chargers. That takes half a second, surely easy to do in good time?

[Jim Webster]

Remember that with the front (or rear) of a unit you've got the veterans as file leaders and veterans at the back as file closers.
The guys in the middle who suddenly find themselves in the front rank might just be the men who were put towards the back because they weren't so well trained, equipped or motivated.

Another thing to remember is that if you're attacked from the flank, your flank support has gone. Hoplites are the men whose formation drifted so that they snuggled under their neighbour's shield.

If your flanks have gone and enemy cavalry is to your flank and rear your army is in deep trouble, but not half as much trouble as you are in

Jim

[Sharur]

All the infantry need to do to prepare for a flank charge is turn 90 degrees to face the chargers. That takes half a second, surely easy to do in good time?

An infantry unit in combat is expecting to deal with an enemy to its front.

If attacked from the side, while for an individual who becomes aware of that fact in advance, turning would be relatively quick, at least theoretically, assuming the press of bodies, length of weapons and any shield carried might allow them to turn to face the new threat, how many people will even be aware of it? Many further down the line won't be able to see it, though they may be aware there is a problem because a commotion is going on before the charge hits. A good proportion of those who theoretically could see it won't realise until their comrades nearby point it out to them - if you're scared (as everyone is in battle) and facing as directed by the unit commander, or as most of your colleagues are regardless of the presence/existence of officer-class leaders, you won't be looking around much on the off-chance somebody might be approaching from a different direction. At which point panic could easily set in and morale factors take over, even before the attack presses home.

Plus as Jim rightly said, the cavalry will be partly behind the infantry group in a flanking attack, so what you'll quickly end up with is a formation crumbling as some people turn to the side and others to the rear, not really knowing which is best, to try to counteract the threats suddenly posed in wholly unexpected directions.

Hence the preferred to doctrinal use of square formations for infantry defending against cavalry in later (gunpowder) times - no flank, no rear, no panic in trying to turn.

[Imperial Dave]

There is the morale effect for definite but also, and I am happy to be corrected, a side impact may mean there is not enough time to reorganise the infantry and "brace for impact"?

All the infantry need to do to prepare for a flank charge is turn 90 degrees to face the chargers. That takes half a second, surely easy to do in good time?

Under battle stress and perhaps maybe unsighted until the last moment with the best of your men in the front ranks not the side? If nothing else, the confusion caused by a flank attack at the same time as a possible frontal attack would put even an organised veteran unit under extreme pressure

[Erpingham]

I think the directionality of a formation is a key factor.  As has already been said, a body of close-combat infantry is organised to fight to the front.  It has a "grain" as it were.  It is physically aligned in on one direction, its weapons and defences point that way, its leaders are positioned to fight it in that direction, its situational awareness is forward.  Hit from the flank (or as has already been said, enveloped from the flank - most of a linear formation is going to flow round the rear) causes immediate confusion.  In a body where you are quite literally relying on someone to cover your back, uncertainty about whether you are covered is unnerving and will cause unit cohesion to at least falter, if not fail.  Given your situational awareness faces forward and inside a formation is going to be limited anyway, a load of shouting and weapons clashing to your left or right that you can't see the cause of is not going to do your focus and motivation much good. 

The point about penetrating the formation is a good one.  The cavalrymen are going to bog down hitting a dense milling crowd, even if they are not getting much resistance.  If the infantry don't disintegrate and reform a defence, they are in trouble.  So, the infantry's morale, experience and leadership are important.  Also, I think, the infantry are more likely to hold together if being attacked from only one direction.  The hoplite scenario discussed, with a phalanx attacking the front and a cavalry attack from the flank would be very hard to recover from.

[aligern]

At Adrianople the effect of the Gothic cavalry attacking from the flank appears to have been to crush in the Roman infantry. This prevented them using their weapons effectively and IIRC caused them ti injure each other. I think the effect of the Africans at Cannae  on the Romans is something similar.

I surmise that flank attacks cause the victims to recoil backwards, probably instinctively, which destroys the spacing and the small unit cohesion and cooperation which gives mutual support and confidence.
I do often raise this business of small group coordination in Ancient warfare. Units that keep the same men in the same positions have an immense advantage over any that just split men arbitrarily into ranks and files.  The Hoplites have a system that allocates  men to file positions so that a good man is at the back, the best men at the front. The Strategikon does much the same.  When we debated the Greeks sending men out by age group I postulated that this had to be by ranks because otherwise the integrity of the unit would be compromised. No one picked that up. When a unit organised this way is attacked in flank it cannot just turn as though everyone was equal in ability. Moreover there is the question of who will order this turn?, how many men in each file will turn? Do the Front three ranks keep fighting to the front and the back five turn to the flank?  Unless a formed square or circle is set up the unit will collapse away from the attack and end up too jammed together to be anything but victims.
I recall too that in Plutarch there is an example of Parthian cataphracts driving in the Legionaries so that they were too close together to protect themselves against incoming arrows.

Roy

[Patrick Waterson]

A good set of responses which seem to touch on all the significant factors.

The original question is still important, because if we take the phalanx-to-front-cavalry-to-flank hypothesis concerning Chaeronea, Companion cavalry arriving from the Theban flank can run through the (say) ten deep sacred Band, although the likely 20-yard wide wedge formation woudl give half the cavalry nothing to do, but then we have 12,000 or more hoplites, 8-10 deep and hence 1,200 to 1,500 wide, for the cavalry to get through if they continue travelling in the same direction.  That would mean about three quarters of a mile of constant prodding, stabbing and hewing before they arrive at - the centre of the enemy army.   To me this seems like rather exhausting work, and if they want to continue in the same direction they will have at least another three quarters of a mile to go.

For this reason I would see a flank attack by cavalry as attempting to 'bite off' the rear corner of an enemy infantry formation, then pouring past and redeploying (or at least refacing) for an attack on the opponents' rear.  Successive cavalry formations might attempt to gouge out another chunk of hapless enemy infantry from the end of the line, while friendly infantry should in theory make short work of the remaining attenuated ranks.  All in all, the effect of a cavalry flank charge against an eight-deep line or similar seems a bit like trying to use a razor to slice butter off a piece of bread.  Far more effective, it would seem, would be to ride round to the rear and hit that, meanwhile delivering a javelin or two while passing the flank, which would be especially effective if done against the unshielded flank (the right) of the opponents.

This assumes that the attacked infantry do not suffer a failure of morale as a result of cavalry swarming round their flank and rear.  If they do then they break and the pursuit and slaughter stage begins.

An opponent with a deeper deployment, e.g. Romans, would seem more vulnerable to the immediate consequences of a cavalry flank attack.  Rather than just one line to skim there are three, and proceeding between these lines could in theory allow several simultaneous 'close shaves' progressively to scour men off the front and rear corners of each formation.  In practice the lines may have deployed sufficiently close together to make this practice extremely risky: at Bagradas and Cannae the Carthaginian cavalry curled around the rear rather than try to pour between the lines as part of a flank attack.

The effect of a cavalry flank attack on an infantry formation might thus be likened to a scourer wearing down the corner as it goes past, with cavalry squadron after squadron striking down a few more men each as they ride past en route to the hapless infantry's rear and hence thinning out the line on that flank.  Once they line up along the rear the real fun begins.

At least that may be one way to understand the likely process.  Other suggestions welcome.

[Imperial Dave]

My small take on it would be to liken the infantry formation to a football fan "scrum". If you've ever been to a massive football game and come out of it with several thousand other people you will understand what I am about to say!

If you have a tightly packed infantry formation fighting to the front, a hit on the flank gives you problems in addition to the mentioned the "turning to face in time/shieldless/not your best men" aspects 

Tightly packed men have a problem with movement in that once a direction of flow is started its very difficult to change that. So lets suppose the front of the infantry formation is engaged heavily and is being pushed backed (or pushing forward) and the first few ranks are very compact. If hit in the flank,

a) it will be difficult for tightly packed men to turn to face this threat (other than a few immediately facing the new threat) and
b) the formation will be compressed in a new direction (ie perpendicular to the forward/backward pressure of the frontal motion/combat).

If thats the case, we now have a football scrum with men in the middle of the formation unable to effectively operate in support of the front or side facing troops in combat. They have to choose which line to support and even if there were all of one mind they are "pinned" by the movement of their fellow comabatants in two directions. Having been in a football scrum, you have no control over where you are going as an individual and its quite frightening in its own right. Add to that the thought of sharp pointy things coming your way and panic will set in.

I think to take Patricks point about depth/distance to cover by a flank attack forward, the flank engaged troops would take a fearful hammering until ultimately the "scrum" behind the combat interface would eventually fragment (as an effective force) under bilateral pressure/movement 

[Erpingham]

I, like patrick, think we are closing in on the answers.  Dave's point about crowd behaviour is significant.  It is a mistake to see a military formation as a crowd, even an irregular one.  It is spaced to allow people to be able to move, use weapons and be relatively sure of their footing.  If you compact this, especially from multiple directions, it risks becoming Dave's crowd, in which you can do little other than move with the herd.  So this is one thing that is in play in a flank attack, even if it is only fear of it happening.

Another thing is that there tends to be a lack of understanding of the difficulties in delivering attacks other than straight ahead.  I think wargamers are particularly prone to this because many rules allow troops not engaged to the front to pivot round onto the flanks of the enemy.  In reality, you needed space to manouever into position - it took time.  As to attacks against the rear, they probably were preferred, but took even longer to set up.   A flank attack is going to envelope the rear anyway, applying three way pressure on the enemy.

[Imperial Dave]

I, like patrick, think we are closing in on the answers.  Dave's point about crowd behaviour is significant.  It is a mistake to see a military formation as a crowd, even an irregular one.  It is spaced to allow people to be able to move, use weapons and be relatively sure of their footing.  If you compact this, especially from multiple directions, it risks becoming Dave's crowd, in which you can do little other than move with the herd.  So this is one thing that is in play in a flank attack, even if it is only fear of it happening.

Another thing is that there tends to be a lack of understanding of the difficulties in delivering attacks other than straight ahead.  I think wargamers are particularly prone to this because many rules allow troops not engaged to the front to pivot round onto the flanks of the enemy.  In reality, you needed space to manouever into position - it took time.  As to attacks against the rear, they probably were preferred, but took even longer to set up.   A flank attack is going to envelope the rear anyway, applying three way pressure on the enemy.

Taking it a bit further Anthony, a thought just occured to me regarding our "crowd" analogy.....what if a flank impact could be likened to a domino effect. As a force hits the flank, people get rapidly compressed against their surrounding fellows which could set up a ripple effect throughout the entire formation, possibly knocking people off their feet or at worst unbalancing them badly and thus forming our disorganised, compressed crowd. Then we have the continued forward pressure from the flank attack which generates further motion and the crowd is pulled this way and that as per my original musings

[aligern]

I go for the ripple effect and the degradation that crowding and compressing imoses on troops, especially with shields and shafted weapons. There is no need for attacking cavalry to  bite off a cirner, in fact that would be pointless as the enemy formation would re assert itself. The flanking units just keep up a steady pressure and lap round the rear and keep the crowding effect going. They have no need to try and get through the enemy formation for theoretical 3/4 mile because the hoplites are being attacked from the front and the crush from the side interacts with this sequentially along the line.

Isn't it Ardant du Picq who describes a shudder running through a formation . Human beings in a crowd, or mass formation have a group mind which overtakes their individual reactions. When fighting and pushing to the front the impact of men recoiling from the flank destroys the cohesive firward fighting system so the majority of men cannot resist in either direction,

Of course it takes time for the panic from the flank to reach the centre which may break through to the front before it is fixed.
Roy

[Imperial Dave]

The flanking units just keep up a steady pressure and lap round the rear and keep the crowding effect going. They have no need to try and get through the enemy formation for theoretical 3/4 mile because the hoplites are being attacked from the front and the crush from the side interacts with this sequentially along the line.

Agreed and in our proposal, a compacted infantry mass (resulting from the initial flank impact and possible frontal combat pressure) will necessarily lead to a flattening and lapping effect of the flank chargers....thus leading to more compaction as the flank is enveloped possibly to include the rear as well

Its a chain reaction and one that I can see would be irrestitable once started (and if maintained rather than broken off for another charge)