Instances and Interpretations of Interpenetration

[BjörnF]

I have always wondered if one of Hannibal's problems at Zama was that he didn't know how to make HI pass through other HI.

From wikipedia about Hannibal's first line: "After a close contest, his first line was pushed back by the Roman hastati. Hannibal ordered his second line not to allow the first line in their ranks. The bulk of them managed to escape and position themselves on the wings of the second line on Hannibal's instructions."

About Hannibal's second line:  "Again, it was not allowed to merge with the third line and was forced to the wings, along with the first line."

I mean, the Romans did also fight in lines and could get an exhausted line through the line behind it without killing their own men.

[Patrick Waterson]

I have always wondered if one of Hannibal's problems at Zama was that he didn't know how to make HI pass through other HI.

He knew - he had been doing it for more than a decade in Italy.  Most of his troops, at least in his own army, were Italian and familiar with the Roman system, which he had anyway adopted.  Training Mago's mercenaries and Carthage's citizen infantry in line exchange would have taken only a few weeks, and he had those prior to Zama (when the Carthaginian senate wanted to hurry him up to engage the Romans, he told them to mind their own business, which suggests that he was not pepared to move until happy with his units' training).

The reasons for the mix-up between the Carthaginian first and second lines have more to do with Scipio's anticipation of and countermeasures against Hannibal's plan for the battle.  The elephants and first line, split into company-size 'combat groups', were supposed to break into the Roman hastati and force them back on the principes while the second line moved up behind and scooped up any bypassed hastati, like a rake being pressed points-first into the Roman lines.  At the same time, Hannibal's veterans were supposed to envelop the Roman flanks (hence their deployment well back instead of in support of the second line).  However, when Scipio spooked the elephants and drove off the Carthaginian cavalry with his own, Hannibal's envelopment was aborted and this meant the leading lines were unsupported.

Hanibal had doubtless instructed his second line to maintain their cohesion at all costs, but the disruption of his plan meant they hung back from following up the first line, perhaps waiting for the veterans to move out and envelop the Romans (which of course never happened), which meant the unsupported first line ran out of momentum and by the time the second line closed the survivors of the first were seeking to get away.  Drill or no drill, the result was an all-round mess.  The Romans eventualy won the resultant three-cornered fight, which left the survivors of the Carthaginian first and second lines routing full pelt towards the third line.

The third line, consisting of Hannibal's veterans, was fully capable of letting another line or lines through, but in a controlled fashion.  The routers were very much uncontrolled, so rather than have his last steady troops mobbed and disorganised by panicky routers shoving through with intent rather than order, Hannibal preferred to send them round the ends of his third line, keeping the latter intact and ready for immediate engagement.

Hannibal knew how to pass HI through other HI, but the dislocation of his arrangements at Zamam meant he faced an entirely different problem than an ordinary exchange of lines.

[Erpingham]

Just checking Chris got what he wanted here - it seemed to stop abruptly.

I think we demonstrated evidence of light infantry interpenetration in the ancient mediterranean, plus Romans could do it with heavy infantry.  Patrick holds that Hannibal's veterans could carry out HI/HI interpenetration.  The Byzantines could pass cavalry through an infantry line when the infantry was deployed to allow it to happen, as well as deploying light infantry through those same gaps.  Cavalry passing through infantry gaps seems implied in much Early Medieval warfare, where cavalry could take shelter behind an infantry wall or in an infantry hollow formation.

There are a number of other queries.  Charging elephants and scythed chariots could be channelled through hostile infantry.  Does this mean they could channel through friendly infantry? 

These examples are mainlydrawn from Mediterranean wars or sometimes Northern Europe.  What was the situation like further East?  Did the Chinese, for example, do interpenetration?

[Jim Webster]

There are a number of other queries.  Charging elephants and scythed chariots could be channelled through hostile infantry.  Does this mean they could channel through friendly infantry? 

In the Elephant battle, (Galatians v Seleucids) we're told that the Galatian infantry opened their ranks to let their own chariots move forward

[Chris]

Just checking Chris got what he wanted here - it seemed to stop abruptly.


Yes I did Anthony. Thanks for checking in on that. As for what I am going to do with the information, well . . .

A survey of rules (those that I have played and those that I have not - perhaps 9 or 10 books in total) has been considered, but to what end? Interestingly, at least to me, there are a couple at one end of the interpenetration spectrum (like Armati and Tactica) and a couple at the other end (like Hail Caesar and WRG 3rd Edition - 1971). The majority seem to fall somewhere in the middle. Accepting the historical exceptions noted in previous posts, a brief look at Battle Day engagements (say the last 10) and looking over the diagrams of battles provided in Warfare in the Classical World suggests that encounters were rather linear, obviously, and so, there was not a great need for this friendly formation to pass through this other friendly formation. So, while there are sections of rules that cover this possibility, it appears that the frequency of it happening was not all that common. Others, in previous posts, have remarked that interpenetration is more of a game mechanic. So, like the various approaches to this diverse hobby, it seems a case of "to each his own".

FWIW, the topic has only been covered once in the pages of Slingshot, at least as far as I know. A check of the Index showed that Richard Nelson looked at the subject from a WRG 4th Edition perspective in Issue 52.

At this point, will probably put this topic on the "pending further consideration" shelf, right next to the idea about writing an article or articles about terrain.

Cheers,
Chris