Roman Battle Formations Mid Republic to Late Rep.

[Vindex]

Gentlemen - please keep to the subject of the thread as the topic of your discussion and avoid personal references or sniping. It is spoiling an otherwise interesting topic.

[Timus]

I posted a reply yesterday but my answer never went online : /

Tim NC,

Where in his commentaries does it say eight legions?. He brings up Delbruck and Keppie, who I havent read, who state Pompeius only had 88 cohorts, stating 110 was too many. How did they get those numbers? [.........]
.

For Pompey's army, apparently Caesar "forgot" to account for various detachments Pompey had sent away from the army. And in the end, he captured "only" 9 Eagles.

For Caesar's troops, in the pages describing the battle, he only IDs 3 legions (8, 9 and 10) and says he had 80 cohorts in line AND 7 cohorts guarding the camp. So it's a bit more complicated than just 8 Legions obviously. Caesar mentions he left Italy with 7 legions, then Antoine joined him with 4 (including 1 of recruit).
However when you read the chapters leading to the battle, CJC says things like "Legion Y and Z, under Publius Somethingus were sent to ...blabla..." and then some pages later, "the army having reunited with "....". I had a quick look at those pages, and it seems out of the 11 legions, he's just missing the recruit one (n°27). But he also has various cohorts scattered around on garrisons duty. And it's not completely clear whether or not they got back to the main army before the battle. And there other issues. For instance he leaves twice a 3 cohorts garrisons in Oricum...

In the end I think it's possible to ID up to 6 legions with a good degree of certainty which does leave us with 27 cohorts of unknown provenance and 5 legions unaccounted for, including one (the 27) almost certainly away from the army.
- 8 9 and 10 are certain
- 6 (present at Dyrrachium and then had to follow Caesar to Alexandrie), 11 12 (under Cn. Domitius Calvinus)
The most likely candidate for the remaining legions being the 7, 13 and 14. Which still leaves one last legion.

To come back to Appian. He has Caesar at 21 000 line infantry, of which 2000 ("the oldest ones"... so his best veterans) are left to guard the camp and 3000 ("of his bravest foot soldiers") used to make up the 4th line. Which leaves poor Caius with only 16 000 in his main battle line to face 37 000 infantry (minus light troops though). I would not follow Appian who himself acknowledge that he is really not sure which source to follow.

Regardless, at Pharsalus, in order for Caesar to have matched the length of Pompeius' vastly superior battle line, with his limited numbers and cohorts, Caesar's ranks would have been much smaller. Either that, or as Michael J. Taylor theorizes, he extended the gaps between maniples. Since we're talking about half the numbers, I doubt the gaps were doubled to make up for it. The easiest thing to do would be to half the ranks, especially if you have confidence in your men to hold, which Caesar appears to have

Well Caesar had understrength legions with understrength cohorts, so he must have used every trick in the book to match Pompey's line. Who kinda "helped" him by deploying his lines 10 ranks deep and probably didn't trust his troop with anything more than minimal gaps. So he probably used a combination of both. But the shallower the formation, the more dangerous the gaps would be or at least would feel for each century/maniple.

[antiochus]

Deleted

[Bryan]

the content of this post has been removed as irrelevant.

[Renatus]

Polybius does mention cohorts, so what is the problem?

Could you give a reference? I would like to see what word he actually uses.

I also stated in that posting on Rat you could make your judgement public to RAT. As you have elected not to I respect that.

Sorry, I don't seem to have received that one.

I’ve discussed it in various threads when I thought it was appropriate to that thread. But here it is hopefully in one bag.

I was thinking of your book, which I hope will contain a (possibly, quite lengthy) introductory section fully explaining the principles upon which your theories are based.

[Macedon]

Yes, he does, he actually calls it with its latin name "koortis". In 11.23.2 "τοῦτο δὲ καλεῖται τὸ σύνταγμα τῶν πεζῶν παρὰ Ῥωμαίοις κοόρτις" and in 11.33.1 "ἐπὶ τέτταρας κοόρτις προσέβαλε τοῖς πεζοῖς". In the first instance he wrote that a koortis consists of 3 speirae (what we regularly call maniples) along with the usual grosphomachoi (regularly rendered as javelineers or sometimes velites) and the second instance is in actual battle.

[Bryan]

Yes, he does, he actually calls it with its latin name "koortis". In 11.23.2 "τοῦτο δὲ καλεῖται τὸ σύνταγμα τῶν πεζῶν παρὰ Ῥωμαίοις κοόρτις" and in 11.33.1 "ἐπὶ τέτταρας κοόρτις προσέβαλε τοῖς πεζοῖς". In the first instance he wrote that a koortis consists of 3 speirae (what we regularly call maniples) along with the usual grosphomachoi (regularly rendered as javelineers or sometimes velites) and the second instance is in actual battle.

Outstanding find. But I think its telling that Polybius chooses not to describe the cohort as a standardized unit of the Roman legion in Book 6 where he discusses organization, but instead refers specifically to Scipio Africanus and Gaius Laelius using cohorts. Which would lead back to the theory that a cohort was an adhoc unit only used by certain people in certain circumstances, until over time it became more standardized in usage during the time period of the Late Republic.

Here's an Interesting theory:
Using the unit grouping method common among the allied Ala, Scipio Africanus begins dividing the Roman contingent of his army into cohorts to make detaching units easier. Laelius, a novus homo, a close friend of Scipio Africanus since childhood, and is possible client of the Cornelii Scipii, does the same, as he learned of cohorts from his friend who he campaigned with. The family of the Cornelii Scipii and the Aemilii Paullii are inter-related through marriage. The son of L. Aemilius Paullus Macedonicus, no doubt familiar with Gaius Laelius (friend of family) and the history of Scipio Africanus, his uncle by marriage, so the concept of using cohorts would have been quite familiar with him and would have been part of his military education. Later, he is adopted directly by the son of Scipio Africanus the Elder. During war against Numantia, a young Gaius Marius is attached to the staff of Scipio Aemilianus Africanus and is seen as a promising Roman leader, in a war that would required medium sized detachments to be used unconventionally because of the trying nature of the siege/war. So Gaius Marius learns from an early age about the benefits in using cohorts. Later, as a praetor, he serves in Spain chasing "bandits," where the use of cohorts probably helped. Later, he serves under Caecilius Metellus as a legate in the war against the Numidian King Jugurtha, which due to the enemy Rome faces, sees a similar need for units smaller than legions and larger than maniples to be frequently, detached during raiding and foraging missions as an example. He goes on to supersede Metellus, taking over command of that army/campaign. During the last decade of the 2nd Century BC, Marius serves continuously as a senior legate for a consular army for two years and then commands successful armies for another seven years, during the Jugurthine and Cimbric War ( total of 2/3/4 years). There is no way to know how many junior officers, contubernales, tribunes, legates, and such served under him during this time, but there would have been a lot, since the two wars, especially the Cimbric War, were of great importance to Rome's future. That's not even counting those that would serve under him during the Social Wars, or those that would serve under his direct proteges. Up until that period, no one served so long in command non-stop since Hannibal's War against Rome a hundred years before. Some noteable figures that are known to have served under Marius are:

- Sulla, the next great military leader of the time period serves directly underneath Marius during not only the Jugurthine War, but also for most of the Cimbric War as well, before he goes off to assist the Consul Quintus Lutatius Catulus as a legate, no doubt bringing with him a level of military expertise learned directly from Marius. He goes on to have a successful pro-consular command in the Social War, where he is awarded the Grass Crown. Later goes on to command the war against Mithridates of Pontus for many years, as well as commanding armies and the overall campaigns during the Civil Wars.

- Sertorius who was known as a military superstar. He is awarded the Grass Crown in Spain, before the Civil War starts. He beat up on multiple Roman generals, including Metellus Pius and Pompeius Magnus (both proteges of Sulla, the former who served with Marius), in a semi-unconventional civil war in Spain.

- The brothers Sextus and Gaius Julius Caesar, both brother-in-laws with Marius; the former which would hold a senior consular command during the Social War, the latter who was a praetor and the father of C. Julius Caesar Dictator, who directly used a system of military tactics revolving around the use of cohorts.

Coincidence? I think not.

In addition to the use of cohorts, an advanced training method involving marching and sword and javelin drill was also reportedly in use by Scipio Africanus, Scipio Aemilianus, and later by Rutilius Rufus and Marius, both who served under Scipio Aemilianus. Again, Marius had taught so many junior Roman leaders that later commanded armies, the training methods he practiced, learned from others, later became the "standard" for Rome's armies.

[antiochus]

Deleted

[Renatus]

I also stated in that posting on Rat you could make your judgement public to RAT. As you have elected not to I respect that.

Sorry, I don't seem to have received that one.

Subject: The Roman Army of Diocletian, posting #349655:

“So if you are interested Renatus let me know and I will send an electronic version. The only drawback is you must agree to keep the material private and not share it around. However, that does not mean you cannot make postings on this forum stating my research is bollocks and I am mad and should be shot.”

Ah, now I see what you mean.

[Macedon]

Now, people...

I tried to remove all irrelevant bickering. I will not occupy myself with who started it, who is right and who is wrong, I will just say, that such conduct is unbecoming, especially when Moi already warned you. This is the second warning and there will NOT be a third.

[Gunthamund Hasding]

Well let me just throw more into this fire
I think there was no STANDARD whatsoever in aligning a legion/army
There was a standard legion sure and we know about but when it comes to deployment there was none, there were only choices an commander had to do, that is whey they were learning by example, if you carefully read Caesar you will get what I mean he arranged his battle array depending on the circumstances and he often won because of the way he array his peeps

[Mark Hygate]

Well let me just throw more into this fire
I think there was no STANDARD whatsoever in aligning a legion/army
There was a standard legion sure and we know about but when it comes to deployment there was none, there were only choices an commander had to do, that is whey they were learning by example, if you carefully read Caesar you will get what I mean he arranged his battle array depending on the circumstances and he often won because of the way he array his peeps

Well, firstly thanks to Bryan for reviving this thread - I have read it all.

As to a 'standard' - yes, I am a firm believer that there was a standard - and it's how the Romans were trained. I think I'm quite happy now with my interpretation of the 'triplex acies' and whenever we read that for a pre-Marian/cohort-based army then it probably formed up like that. Funnily enough I am not so sure we should rely on that description after the pre-cohort army disappears, even if it is used.

Once the cohort-army appears then the tactical unit of maneuver seems to change and yes, good generals can exploit that - but it is not unreasonable to think that the cohort then fought in a fairly standard way and the general relied on them to do so. The 'secret' is simple - train and train and train and then get clever when the situation demands it, for you have a good base upon which to innovate.

As to 'gap's - I am anti-gaps for a fairly fundamental reason...

Whilst Roman military history may be my favorite, I have studied most of them at one time or another. Stopping an enemy from penetrating that front line (whether it is contiguous on a single battlefield, or dispersed over a wide and mobile front), has been a basic precept throughout. Forces and methods have been developed to also try and accomplish just that.

More at issue - we here have also brought up examples of the Romans trying to break up things like 'phalanxes' by getting past the pikes even, let alone an actual gap left between formations. The 'manipular tactic', the 'saw formation' (one and the same?), the 'wedge', the 'boars head', the 'column', and the pike phalanx itself all are apparently designed to achieve that break-through of the 'line'.

Times when gaps are deliberately created and (the Xenophon example particularly) you don't form a line are the rarity, for special occasions, and thus talked about.

The classic ones we all know about - the details of Cannae and Zama - I am now comfortable with. I'd like to put them together in an appendix for a possible interpretation of the manipular-legion-based 3 lines - but are there any others that people might wish to see me try and cover? 3rd to 2nd C BC to limit to the likely period of said structure - 'cohorts' would be after.

[Bryan]

Mark wrote:

More at issue - we here have also brought up examples of the Romans trying to break up things like 'phalanxes' by getting past the pikes even, let alone an actual gap left between formations. The 'manipular tactic', the 'saw formation' (one and the same?), the 'wedge', the 'boars head', the 'column', and the pike phalanx itself all are apparently designed to achieve that break-through of the 'line'.

Ignore what I wrote about breaking phalanxes earlier in this thread. Matter of factor, ignore everything I wrote about cohort sized gaps, piston tactics, and maniples in deep formations operating as "wedges." Though I made a few good points about gaps existing, using sources, as to the width or purpose, everything else was unsupported conjecture. But I don't need to describe how maniples beat phalanxes (pike, not hoplite type). Polybius already did that (Pol. 18.27-32). Maniples formations can more easier maneuver on bad terrain common on many battlefields and can break apart for smaller unit actions, such as exploiting gaps in an enemy force (Pydna as example), while a phalanx (continuous line type) can't without sacrificing the integrity of the line. Phalanxes generally have only one line, so its important they hold that one. Romans have many lines (in most fights) so the second or third lines can support exploitation efforts against the first.

Cohort formation staggered front to back would have been no real different from a normal maniple triplex acies except for the fact that the units would be more confident in one another to be properly supported from the rear (or less, should they know the rest of maniples in cohort aren't actually very good). If a cohort was staged with maniples formed side to side, like in the description of Caesar's 4-3-3 formation, it could still mean either small maneuver gaps between maniples or larger maniple sized versions between them.

Whilst Roman military history may be my favorite, I have studied most of them at one time or another. Stopping an enemy from penetrating that front line (whether it is contiguous on a single battlefield, or dispersed over a wide and mobile front), has been a basic precept throughout. Forces and methods have been developed to also try and accomplish just that.

I agree completely if the unit only has one main line and possibly a smaller reserve that shouldn't be committed too early. However the Roman bread and butter formation had three lines, the second which was almost immediately behind the first, directly supporting it, though outside of hand to hand combat or missile range. That's one of the methods that has been developed to counter the thread of having your lines broken and the enemy pouring through them. In the case of the Romans, only a completely disordered retreat by the hastatus could lead to the collapse of the principes or triari. An ordered retreat of maniples to be relieved, or an advance of units of the second or third line could plug exploitations in gaps immediately.

But I think the use of gaps would have been situational dependent. The terrain and enemy faced, as well as overall strength, are some pretty large factors to contemplate when thinking about putting large gaps (maniple in closed array wide) between units. Small gaps would always exist in a healthy fighting line between flexible units, even in contact, as units need some wiggle room to move freely through bad terrain and to advance/retreat. Jamming units/men up against each other in line and expecting them to walk around a tree or bush, or hop over a small creek bed, would be quit amusing to watch.

[ValentinianVictrix]

If the maniple with gaps between formation was so good Bryan then why was this abandoned during the Imperial period and later?

[Bryan]

Are we sure it was abandoned? To be honest, my knowledge of Roman history gets kind of fuzzy during the Principate. I know of it but I'm not as familiar with the sources as I am with the Republican era ones.
If there were changes, they could be the result of changes in mindset, military culture, and customs leading to a change in tactics. It could be as simple as an emperor with an infatuation with the writings of Greece and Alexander and using his influence and power to change the military tactics of Roman legions. That's complete conjecture though, I don't really now the answer, someone else would have to answer it.

Also, I believe there were lots of other differences than just gaps between Republican armies and Imperial and later versions. Equipment, overall tactics, staffing, emphasis on auxiliary units, methodology, enemies faced, etc. Apples and oranges to compare really.