Functionality of the triplex acies

[Robert Vermaat]

But triplex acies does not necessarily imply the quincunx, does it? You can have three battle lines without gaps, I mean.

Of course. Roman armies could form 'phalangial' (NOT 'phalanx') formations which formed battle lines, 8 to 16 deep, without gaps. This became the common battle formation during the Dominate and after, but from time to time earlier Roman generals also made use of it.

[Macedon II]

According to what we know about the distance between lines it does not look like there was direct guarding of these gaps. In Byzantine times the lines stood a "bowshot" apart which, again according to the manuals was considered about 350 yards. The Roman lines of the era in question (and of the checkerboard formation) are considered to have been more than 100 yards apart, effectively outside even from javelin range. This makes any idea about "pockets of death" or maniples attacking the enemy who "dared" exploit these gaps sound a bit too bold. Plus, we are talking about a system that is supposed to have lasted for centuries. Certainly, if the Romans fought in any other way rather than in line, we would have at least some hints at how this system was employed or the countermeasures that would have been devised to counter them. For example, there would be no reason for bursting crazy through the gap as the Persian cavalry supposedly did at Arbela, the Greeks would just have to poke with their long sarissae against the sides of the legionaries or have light infantry exploit those gaps, if they were too scared to push in themselves in a controlled way to pock at the sides. If anyone tries to imagine lone maniples in the form of a rough line with such large gaps among them, we are forced to look at them as maniples in a testudo-like formation that has to have shields on both flanks. Surely such a peculiar formation would have been described in action. Anyways, I have also tried to find texts in support of the checkerboard formation having been employed in battle, but I have not really found anything of value, whereas I have come across multiple examples of the Roman line being clearly described as an uninterrupted line. I would welcome any direct quotes that have to do with the manipular line or the way the lines relieved each other (for example in Zama it seems that individual officers ran to the support of the men in the front, while in Byzantine times it is done by line).

What is very interesting is that what I was expecting to find about the Romans I did find in the description of the battle of Sellasia, where Antigonus seems to have sent up the hill his phalanx in such units with light infantry in the gaps against the troops of Cleomenes' brother. Yet, it is clear that this happened because of the rough terrain, so it was actually the heavy infantry which was supporting the lights rather than the other way around.

[Macedon II]

What do you mean by "phalangial" but not "phalanx"? The definition of the word phalanx is men in relatively close order standing in a rough line. The Celts deployed in phalanx as did the Greeks. Or is it that you want to differentiate with the Greek phalanx?

[KET]

Greetings,

Although we cannot be sure one way or another, this is an interesting discussion none the less. I suppose, even though I have read many studies on the subject, I never imagined anything so neat or formal as what has been discussed. In my mind's eye, I always viewed the gaps between the maniples and the three lines to be primarily for maneuver and reserve. It is my belief that. like in the 18th/19th centuries, what happened on the battlefield and what was spelled out in the drill manual were not necessarily the same.

Certainly, moving a long battle line with any type of speed or order over any type terrain would be difficult at best. But the smaller, more compact maniples could move easily and quickly enough in most any direction. This gives an advantage over larger, more ponderous formations.

I picture the lighter hastati engaging primarily in missle attacks and then retiring through the gaps in line of principes before contact to reform on the flanks or rear. This will wear down the enemy, perhaps cause them to deploy early, or even break up their formation.

The maniples of the principes - as many as were needed to match the length of the enemy line - would then converge on said enemy line. Just as the modern maxim "no plan survives first contact with the enemy", I don't image two lines of warriors meeting in close combat as much able to maintain neat formations, and probably not having the freedom (and command and control) to be anything more than a multi-rank mass of humanity fighting for thier lives. In other words, the gaps that allowed maneuver are no longer needed... Those maniples engaged are no more than spent ammunition until a break in the action allows them to reform.

When there are excess maniples of principes, then they are free to flank the enemy or provide other support. If the enemy is more numerous, you always have the triarii to even things out. This method would also allow a reserve to be kept. In many periods of warfare, he who could keep that last reserve often won the day.

It's all speculation, of course, but that is my opinion. Right or wrong. Thanks for listening...

[Robert Vermaat]

Hi George,

What do you mean by "phalangial" but not "phalanx"? The definition of the word phalanx is men in relatively close order standing in a rough line. The Celts deployed in phalanx as did the Greeks. Or is it that you want to differentiate with the Greek phalanx?

Yes, that's what I mean. If you say 'phalanx', everybody starts thinking about Greek stuff, while 'phalangial' indeed means 'in a single linear formation' (as you mentioned about Celts), as opposed to a manipular formation.

[Sean Manning]

Hi George,

What do you mean by "phalangial" but not "phalanx"? The definition of the word phalanx is men in relatively close order standing in a rough line. The Celts deployed in phalanx as did the Greeks. Or is it that you want to differentiate with the Greek phalanx?

Yes, that's what I mean. If you say 'phalanx', everybody starts thinking about Greek stuff, while 'phalangial' indeed means 'in a single linear formation' (as you mentioned about Celts), as opposed to a manipular formation.

Still, there are obvious problems with saying that something which Greek military writers would call a phalanx is NOT a phalanx. I notice that when we talk about the ancient sources, even if we know the original languages, our understanding is often contaminated by the modern-language definitions of Greek and Latin words. I think the best strategy is either to reclaim one of the ancient meanings, or use terms in the language you are writing in. For example, “spearman” and “pikeman” are perfectly clear in English, so there is no need to invent the pseudo-Greek phalangite and distinguish it from hoplite as some wargamers do.

[Robert Vermaat]

I notice that when we talk about the ancient sources, even if we know the original languages, our understanding is often contaminated by the modern-language definitions of Greek and Latin words.

Absolutely. And not only modern definitions, but ancient ones as well. Ancient authors could refer to a spatha as a gladius, and a 5th-c. 1000 man strong unit could perfectly well be referred to as a 'legion'. To name but two.

[Sean Manning]

I notice that when we talk about the ancient sources, even if we know the original languages, our understanding is often contaminated by the modern-language definitions of Greek and Latin words.

Absolutely. And not only modern definitions, but ancient ones as well. Ancient authors could refer to a spatha as a gladius, and a 5th-c. 1000 man strong unit could perfectly well be referred to as a 'legion'. To name but two.

I do like the “phalanx of the elephants” (all the elephants in an army, or the name of the largest unit of elephants) in the Hellenistic tactical writers. We would never guess that going from how we use phalanx in English.

[Titus Labienus]

This is my first post on the board, but I am excited to learn of this site! I am reading an article at the moment dealing with this very issue. It is true, we do not have much in the way of a soldier's-eye-view in the ancient literature. If you have access to a university, you should check out the article "The Face of Roman Battle" by Philip Sabin, The Journal of Roman Studies, Vol. 90 (2000), pp. 1-17. It is available at jstor.org. He cites Polybius (18.29-30) as claiming that there was only one legionary in the front rank for every six feet of coverage. Vegetius (3.14) says three feet. Sabin suggests that the second rank coulave stepped into or out of the gaps in the front rank as needed.

[Tarbicus]

There are ways to test these formations. If you hack/modify Rome: Total War's unit files you can experiment with them. Clearly not ideal, but in the absence of full legions it's not a bad way to model the different theories. The AI's prety good. I tried both the six feet and three feet spacings years ago, and was able to retreat my skirmishers and any battered forward units back through the maniples and centuries, the individual legionaries stepping out of their way as necessary but able to maintain a cohesive front, repelling any pursuing enemy.

[Brent Nielsen]

I have to support George on the continuous line theory. He and I have discussed this many times and the first line for sure has to be one continous formation six to eight men deep. Second and third lines however have a problem. The first line is four cohorts per Legion while the second and third are three per legion. Now here is where George and I got lively....for it is a mathematical impossibility for three cohorts to line up with the same depth and cover the same amount of frontage, there must either be gaps between cohorts or the second and third lines are not ranked as deeply. If second line shifts left and third shifts right so that the gaps are mutually supported the second line can be sent in on their rotation at four to six in depth and the third can do the same and that way continuity of the line is maintained. I have tested this out with hundreds of miniatures and it definitely requires some squared away centurions in the second and third line companies!