Interpenetration & Divisional Attack Formations

There have been some controversial about the new interpenetration rule, mainly about his consequences and his motivation.

About the motivation, you will find here an exhaustive explanation about the size of the empty spaces in the area occupied by a Napoleon's Battles unit. In that discussion, we show that the empty spaces are not wide enough to allow free pass of friendly units in the scale this game is played. But also, in a more grand tactical sense, our motivation was that this is a grand tactical game about the Napoleonic Era, and one of his main changes in warfare was the so called 'impulse war system'. It is far from the aim of this little article a deeply explanation of the 'impulse war system', we will only introduce the concept as far as we have based some of our assumption on it.

The Revolutionary wars saw the rise of a new grand tactical system quite different from the one used in the XVIII century battlefields. The first experiments of this system emerged almost 50 years before the Napoleonic era but one of the first examples we have a detailed account is the battle of Biberach (October 1796).

At this battle the French successfully used the combined arms attack techniques developed from this grand tactical system then starting to emerge and Duhèsme's account of the battle says that:

The two infantry divisions under General Saint-Cyr participating in the assault were deployed in columns, arranged in échiquier, while the cavalry at the rear were prepared to pass through the intervals between the infantry battalions.

This is one of the earliest evidences of the new role of cavalry at the battlefield. This kind of impulse warfare grand tactic system allowed a hitherto unprecedented degree of combined arms cooperation. Meanwhile at the previous linear warfare grand tactic system the infantry was almost invariably positioned at the center and the cavalry was relegated to one or both flanks, at the new system the cavalry could poured through the gaps between the battalions. Of course, other historical accounts can be found of cavalry passing through the battalions, but this was not the main way it was conceived. Most of the accounts refer to cavalry passing through gaps between battalions. And, this grand tactical system was not restricted to the Revolutionary wars, as far as 1812, Marbot says in his memories that:

...during an action near the post-house of Kliastisi on 23 July 1812, for example, it is known that the 23rd chàsseurs à cheval Regiment, standing in the second line, was ordered to attack some Russian battalions in the Tamboff Regiment. To do this, it had to pass through the intervals between the friendly regiments in the front line, and then redeploy into line.

From the calculations at the previous post it was clear that these gaps between battalions were not included at the Napoleon's Battles unit footprint, hence the player should foresee this gaps if he wanted to emulate this grand tactical system.

Another motivation, were the different formations deployed at division level. As an example the division of attack formation prescribed by Napoleon before the battle of Austerlitz , stated (among other orders) that the distance between battalions should be an 'entire distance', that is, the space needed to deploy in line a battalion. This kind of grand tactical mixed order also included other instructions about the batteries and skirmish (that will be analysed at further posts). But in essence, this formations and the modifications finally used by the French during this battle included 'in échiquier' formation for the battalions of a brigade (an issue far from the player decision and control at this game, but covered by the stats and a probe that support among the different battalions was supposed to come from the flanks not from a pass through the rear) and the 'entire distance' precept between battalions (to allow, the pass of the supporting cavalry, the battalions from the reserve brigades or line deployment). From both precepts, again, it seems clear that passing through other units was not the way it was planned to give support. Also, take notice that these grand tactical formations were the zenith of the French army and the 'impulse war system'.

A simply calculation can be made of the implication of maintaining this 'entire distance' and the Napoleon's Battles unit footprint. As you can see at the graphic, emulating in this game the prescribed divisional formations of the French army at the battle of Austerlitz implies leaving nearly 2 inches between brigades. And that is really important; this distance is between brigades, nor battalions. We are not considering or calculating were the battalions are inside the footprint (it would be a tactical issue far from the player's role), what emerges from these calculations is that emulating the impulse war system, and the grand tactics employed by the French army at the battle of Austerlitz as prescribed by Napoleon (26th November 1805), Soult (1st & 2nd December 1805) and Saint-Hilaire (2nd December 1805) forces the players to leave 2 inches gaps between brigades at the Napoleon's Battles scale.

As an example how this intervals were finally used at this battle, the Count of Stutterheim says in his memoirs that when the Grand Duke counter-attacked the French, found them deployed with sizeable gaps along his line where the French Guard Cavalry commanded by Marshal Bessières was able to position itself.

We have discussed other examples, such as the lack of support from the French cavalry to D'Erlon corps attack in Waterloo; where the allied cavalry could only counter-attack once that Picton's brigades had been repulsed and were wavering and slowly giving way. And, also at this battle the French cavalry could only counter-attack once their infantry had been routed. Another example we found was the destruction of Thomieres' brigade in Salamanca. One of the main reasons was that its supporting cavalry (under command of general Curto) appears to have ridden parallel with the center of the column, rather at the head of the column or its flank, and thus could not give support at the initial stages of Packenham and D'Urban's attack. More examples can be found, some relatively clear and others more controversial.

And, General Duhèsme in his treatise on light infantry tactics, practices and training writes about never-used manoeuvres, and among those for example there are the 'changing the face of the line', 'passage of the lines', and 'facing to the rear'.

As a resume, moving through a brigade in Napoleon's Battles implies passing through battalions, and it was not the way it was commonly handled, so that the rules must encourage players to foresee this gaps between brigades if they are going to follow some of the advantages of the grand tactical 'impulse war system' that was characteristic from the Era.

We would like to emphasize again that this discussion is not about 'mixed order' formations of the battalions or squadrons inside the brigade (they are covered by the stats in this game), but about the divisional formations adopted by brigades, (that could also be named as 'mixed order') and that fit the grand tactical scope of the game.

Of course, a huge range of other grand tactical formations are possible (massive columns, linear defence…) depending the available forces, his composition, the terrain and other circumstances, but most armies (as the Prussian at the 1812 Regulations) tried to emulate the 'impulse war system' where possible.

As a resume, (as we already pointed out in previous posts); in real battles, fully cooperation between arms was rarely achieved; only limited cooperation was available where the 'impulse war system' precepts were not accomplished. That is why we feel that punishing interpenetration is required for a better simulation of real battles.