Use of whistles to relay commands in battle

[Macedon]

So your basing what happened in 100 BC on something that was written in the 6th century. So your saying that no military innovation happened between the Romans in the mid Republic period of a civil militia period with politically chosen military commanders to an actual true professional military. The formation is always 4,8,16 men deep, okay show me please.

In order to understand how battle tactics worked we should use every text available that has to do with that issue. Strategicon is invaluable in understanding ancient and medieval battle tactics as are a number of other texts from the Byzantine era. It is actually more important than the description of a battle as we read in in Polybius, Plutarchus or Arrian, since it is about tactics in its pure form. Of course descriptions of historians offer much in that understanding too but they rarely give insight to the actual mechanics. Anyways, it is true that tactics varied, not just because they "evolved" (or even devolved...) but because needs are different. When you have huge populations of barbarians migrating into your dominion, you have to adopt your strategy and tactics to that new reality. When you fight against cavalry, light infantry, horsearchers, in grand plains or in mountainous Anatolia, tactics employed will vary as they did in any specific time. But for thousands of years the mechanics were practically the same, no matter how important the import of the stirrup or the use of the longbow may look to some. Of course there were changes in the Roman army as there were changes in all armies through times, some adopting new weapons, mounting on horses, or reverting back to the use of a weapon they haven't used for centuries.

As far as the depth of the battleline is concerned, there is much evidence and for many armies. Romans are usually attested to deploy 6,8 and 10 deep. Other depths are attested of course too. JC deployed 4 deep against Pompey, Pompey deployed 10 deep. Yet, by reading the manuals and studying these numbers in depth, we see that 4 is considered something like an absolute minimum, oftentimes called "shallow". The same sources tell us that it was deemed to shallow to withstand pressure, that it could not divide in two forming an double phalanx if necessary, since two deep was considered improper to use in battle. Again, lines two or even one deep are attested but only to cover a wide area to practically hunt down fugitives, fleeing enemies or in raids. The fact that most of these details are coming from the Byzantine times does not make them less valuable or less probable that they apply in ancient times too. After all, the ancients actually used more complex tactics than the medieval Europeans, this is also admitted in the Byzantine manuals. If you look for depths in general, then we have references to a unit 100 deep, that is the Egyptians who fought against Cyrus, as Xenophon writes in Cyropedia, some 50 deep units in Greece, 25 deep units in Greece too. But even they usually deployed 8-12 men deep (against the sources give abundant information, so you can ask for more info if you like, I and others will surely reply - I still think that such a discussion deserves a new thread of its own). The Macedonian Greeks fought 8,16 or, rarely, 32 deep.

In order to talk about a specific era, we should of course look for sources describing it and then evaluate them. Do you want to discuss Republican Romans, Late Republican? Any specific eras? If we take JC as our starting point for a discussion, we can observe diverse tactics, unfortunately, if I am not mistaken he rarely if ever talks depths. You can look into Frontinus for more information, he sheds some light to this issue.

Anyways, there is no reason for me to assume that the mechanics governing the depth of the Roman line were different in any of these and later eras. The sources seem to agree that 6-10 is normal, 4 is possible but rare (when an army is very experienced AND less in number than the enemy, in training (Vegetius) etc). Barbarian depths are very rarely attested but again, there is no reason to think that they deployed very deep. A unit 50 deep needs 2,500 men to be just 50 men (maybe 50 yards) wide. I know that this is a later source but Sextus Grammaticus in his Gesta Danorum for example, describes the Danish (Viking) wedge as 10 ranks deep.

How did you come to the conclusion that a depth suggested as the norm by most, if not all, ancient writers for any army including Romans would not work? Did you find any references that the opponents of the late Republican Romans were arranged in such deep formations?

Four (five if you could the separate ones at Arausio) Roman consular armies had been beaten by the Cimbri/Teutone confederation. Gnaeus Papririus Carbo (C. 113 BC), Marcus Junius Silanius (C. 109 BC), Lucius Cassius Longinus (C. 107 BC), Quintus Servilius Caepio (C. 106 BC) and Mallius Mallius Maximum (C. 105 BC)
So these barbarians just used their size to beat the trained and disciplined Romans. Okay, fine, but since the battlefields aren't known or mentioned in detail by any sources that the terrain would have limited the deployment of the width of the German battleline. Going from Plutarch they numbered over 500,000 with him stating that the numbers were probably more not less. So if the terrain doesn't allow you to add width to fight the Romans it would mean depth. So lets play conservative and say that the germans only showed up to each battle with 150,000 men. In one line of 8 deep that would mean 18,750 files (150,000/8 ). Since the Germans are known to carry shields they probably fought in a shield wall. So we'll give a frontage of three feet for each file. So the Germans with no gaps have a front line of 56,250 feet (3 * 18,750). So you're saying that the Germans would had a front of 10 1/2 miles? My guess, they packed them in with deeper ranks.

Where did you come up with these numbers again? I do not doubt you but where does Plutarch describe a German army 500,000 men strong on the battlefield? Of course there would have been battles fought on narrower terrain than that necessary to deploy every man. The problem faced by a 100,000 man army in a 3 mile wide valley would also be faced by a 30,000 man army in a 1 mile wide valley. Indeed in such cases, lines could be deeper than normal (normal being the keyword here), multiple lines could be employed (in contrast to general belief barbarians also sometimes deployed in multiple lines), men left in the camp or in other duties should be also taken into account. Again, a well known advice in tactical treatises is to not employ huge armies, it is worse to have 20,000 good men supported by 100,000 levies than 20,000 good men supported by 10,000 levies. Considering that there is no actual shoving of crowded formations as some would suggest (my personal opinion of course, some very knowledgeable members here do disagree with that and we have discussed it in length especially regarding hoplites if you want to look it up), to have a very deep line, whose members are prone to fleeing lacking experience and adequate training is very dangerous and makes the line actually weaker, since it will give way much easier than an average deep line formed by appropriately prepared men.

Yet, of course, in some cases huge armies would deploy in unusual depths because of reasons such as those you mentioned. This of course has very little to do with the depth of the Romans themselves, especially if you take into account that such battles were extremely rare to dictate a new, universal tactical doctrine for the Romans.

I don't get what you are saying. You concede that the enemies of Rome used slingers, archers and carried javelins. Caesar in De bello Gallico mentions archers. I,7-31 is an example. But then you state that they used them up quicker than the Romans?

I did not understand the relation that missile using troops have with depth, but I did not actually have the patience to carefully read very far back. To my knowledge, according to the tacticians 16 was the maximum depth of a formation IF light troops were to be posted behind in order to support the melee with missiles.

My argument is thus: 1st line of Romans, the hastati maniples, used as columns to pierce enemy line. Organized based off of polybius' description. Since gaps are present the second line of Principes maniples is not a reserve (the triari is the reserve) but is actually used as a front line as well when they are committed. See the bad diagrams I made earlier.

Please give sources for your quotes about Romans fighting on line verses in lines (one means in continuous line the other is an order of battle) during the maniple and cohort state of the Republic. If you can I will concede that argument.

I have still to see one example of how Polybius suggests that a fragmented phalanx was used by the Romans during combat. Polybius (actually no writer) says such thing. There are examples of such formations all (strangely enough) on the Greek side. We have Antigonus in Sellasia using what you call a "manipular" formation which would be a direct translation of the Greek word "speridon", as well as Antiochus' phalanx in Magnesia. Yet, both tactical choices were not the norm and were employed to fit the situation. Polybius and every other Greek writer never described the first line of the Romans as anything else than a continuous, virtually uninterrupted line. The mechanism behind gaps is very analytically discussed in the Byzantine treatises all the way into the 10th century and gives insight into how and when they were used.

I do not believe that any model based on the assumption that the Romans fought in a fragmented line comprised of multiple, virtually independent units (called wedges, cohorts or any other way) of any columnar form would work in an infantry battle. Were they so effective, then I guess that we would have multiple examples and good evidence that they existed. Total absence thereof speaks louder than any argument we could voice.

On the other hand, the second line of the Polybian Romans was indeed a reserve. Again the sources are too clear on this. No matter what mechanism we assume they used in order to support the front line, there is no text pointing to the possibility that they fought with the front line in such a manner as you suggest. If I accept that the Principes kept close to the Hastati only to attack seconds after the former charge in, then we have to dismiss everything Polybius and every other writer said of the line of the Principes. A battle in which the Romans do not seem to have used their triplex acies was Cannae. But even then, they did not employ any gaps in their line. Zama is also a good example to analyze. It is one of the few battles where Polybius (or any other) gives so much detail as to the actual maneuvers of the different units and lines. Again we have no gaps, I guess that the order of Scipio to create gaps is enough proof that habitually there were none and that during actual melee they were not used.

As for the mentions of "lines" these are many. The question is where did you find any other description? I will post some examples when I get home, although I have mentioned some above (read Polybius accounts of Cannae and Zama for example)

So again you're saying that a culture which is based on all males being raised as warriors (they only took warriors when they migrated from Jutland), who walked all around western Europe defeating everyone they encountered for over ten years (Gauls and Germans were the first to ask Rome to intervene in the first place), were ignorant about warfare. They trounced the Romans at five different battles, almost a sixth when Catalus barely kept his men in check when the Cimbri crossed the Po. But they're untrained, undisciplined screaming beserkers?
They would have been broken down in families, clans, lesser tribes, probably with "Big Men", chiefs or thanes commanding them. But they fought in unorganized ranks? Might not of been completely orderly compared to Romans or Greeks but they would have needed some order to not just be successful but to feed them all and later organize them for battle.

I agree with you here. The same applies to other "barbarian" armies too. We have a very beautiful ancient text discussing exactly that by Polybius (second book if I remember well, in the battle of Telamon)... Barbarians were capable of employing quite advanced tactics indeed. On the other hand, you also make the mistake of not differentiating between the percentage of battle hardened warriors and those not more able than any Roman levy who has undergone basic training. Again according to the Tacticians (with who I happen to agree), a sizable percentage of the latter would actually be a hindrance rather than add to the efficiency of the former.

How about this. In order for the trained and disciplined legions of Rome to finally conquer these people it took Gaius Marius reorganizing the legions in some way and then using flanking attacks from hidden forces to win one battle (Aquae Sextiae) and some other form of trickery to win the other (Vercellae).

My take on it:It wasn't a specific Roman order of battle that gained them an empire, it was the ability of men, Generals, centurions and the good old foot slogger. And their ability to never accept defeat even if they lost a major battle.

Anyway, can we copy all this and just put it in a new topic called "Roman Tactics during the Transition From Maniple Legions to Cohort"?

Starting by agreeing to your last proposal, I also have to add that stratagems are attested for most battles. Of course a good general would use everything to shift the balance to his favor, even if it was so in the first place! At Cannae, Hannibal is attested to have ordered a contingent of his men to shift over to the Romans. When the Romans brought them to the rear and returned to battle, these men attacked their guards, took weapons and attacked the Romans from behind (not in Plutarch's account)! Philip's withdrawal in Cheronea was also a stratagem that worked and so on. Stratagems can be very valuable but of course the battle is eventually won by the men in the line. Yet, you should not think that they were the reason for Roman supremacy in general.