Roman battle tactics after Constantine's reform

[auxilia]

Hello everyone,

this is my very first post since I only recently heard of this great forum. The question I'd like to hear something about is in the thread's title.

What I'm specifically into are infantry formations. I read some books and I know a lot about the cohortal legions in battle. But, what about those late legions?

Did they still employ the formations like simplex, duplex, triplex, quadruplex acis?

And how did they use the ordines? I know the legion of the time was made up of six ordines all totaling around 1000-1200 men.

Now, the cohort had six centuries, so I wonder if the late legions actually used similar formations as the cohorts (cohort was usually arranged in a kind of duplex acies - two lines of three centuries)?

 

Any response would be appreciated!

Thanks!

[caldrail]

The various formations, tactics, and strategies employed by the classic legion were still in place in the late empire - However - they weren't as practised in them. The changing operational needs and the vastly reduced size of Roman legions in the late empire, combined with frontier and reaction troops, meant that in the ordinary day to day business of maintaining security (the old battle ready legions were a thing of the past) resulted in a tendency toward raiding and low level warfare (as observed by Adrian Goldsworthy).

 

The biggest indication of that was Adrianople, in which a poorly motivated army was sent into battle in the old fashioned way and frankly couldn't perform as expected, whereas the smaller, fresher, better motivated teams selected by Sebastianus performed brilliantly, as Zosimus records "Heads were returning to Constantinople every day".

 

Nonetheless some of the old military expertise must have existed because for instance Gildas reports that the Romans left advice (and military manuals?) for the newly independent Britons to provide for their own defence.

[auxilia]

All right, thanks a lot.

Although at Adrianople the Roman infantry appears to have been performing very well before they got abandoned by their cavalry.

[Northern Neil]

If you havent already read this, may I suggest the works of Ammianus Marcellinus? They are neatly put together in a work called 'The Later Roman Empire' and published currently by Penguin. Ammianus is very readable, and he goes into great detail about Julian's campaign against the Persians in 361. He describes legions as fulfilling an engineering role with regard to siege engines, and seems to allude to tried and tested formations such as the testudo.

 

I might be so bold as to suggest that Diocletianus' reforms, in which legions were reorganised and reduced from over 5000 men to about 1000, simply tidied up an arrangement that had existed at least from the time of Trajan, when vexillations were sent from a quiet sector to a troublesome one, and took up permanent residence at their new base. I suspect that when Diocletian looked at the whole disorganised mess, with vexillations of legions spread out along 800 miles of frontier, his reforms made the administration of the system a good deal easier!

[barca]

What I'm specifically into are infantry formations. I read some books and I know a lot about the cohortal legions in battle. But, what about those late legions?

 

I recently read Alessandro Barbero's Day of the Barbarians, and he has a good description of the battle of Adrianople. I get the impression that they advanced in very close order, almost like a hoplite phalanx, and they were unable to mobilize reserves to protect their flanks. It may have just been a consequence of poor leadership in that particular situation.

You may be able to get more information on the late Roman Army from Ammianus:

http://www.amazon.com/Later-Roman-Empire-D...7854&sr=1-1

http://www.amazon.com/Later-Roman-Empire-D...7854&sr=1-1

[auxilia]

Yeah, I've heard of Ammianus' work... I'll try to get my hands on the book asap.

 

I might be so bold as to suggest that Diocletianus' reforms, in which legions were reorganised and reduced from over 5000 men to about 1000, simply tidied up an arrangement that had existed at least from the time of Trajan, when vexillations were sent from a quiet sector to a troublesome one, and took up permanent residence at their new base. I suspect that when Diocletian looked at the whole disorganised mess, with vexillations of legions spread out along 800 miles of frontier, his reforms made the administration of the system a good deal easier!

I completely agree with you. In fact, I've always had an impression the Romans simply expanded on the practice of creating the vexillations so they decided to recruit all future legions at the similar strength.

 

I get the impression that they advanced in very close order, almost like a hoplite phalanx, and they were unable to mobilize reserves to protect their flanks. It may have just been a consequence of poor leadership in that particular situation.

 

Is there any evidence which may suggest the way individual ordo was used? It was made up of c. 200 men and I wonder whether it was employed like a century within a cohort (which were highly mobile and any century could have operated independently within a cohort)? Or perhaps the ordines were more static and simply held their ground?

Edited January 29, 2010 by auxilia

[caldrail]

This is turning into an Adrianople debate.. Whoops! My fault. All the same though, the Roman behaviour at that particular battle was confused. The battle started by accident, as some opposing units got a little close to each other and tit for tat reactions spread across the whole line as individual commanders made snap decisions (or didn't) about what to do without orders to begin from Valens, who had assumed command of the army and forged ahead to meet the Goths before Gratian arrived with reinforcements at the urging of his general Sebastianus who was by that time supporting the case for a large battle to curry favour with his boss.

 

Previously, Sebastianus had favoured using small units as raiders to whittle down gothic resolve, and by the time of Adrianople had forced the Goths to forage in large numbers for fear of ambush. Fritigern was after all playing for time when the lines deployed though it isn't clear whether his hidden cavalry was a welcome good fortune or whether he'd placed them there.

 

The point NN makes about vexillations is an important observation because a vexillation is not a standard unit formation, but rather an ad hoc number of troops sent on a mission. The failure of troops to return might reflect on a variety of factors such as command and control, always a difficulty with detached units without instant communications, or perhaps simply a desire to find a quiet spot and sit tight in relative comfort (always a preoccupation of soldiers ). However the size of legions was less dictated by prior events than a recognition that times had changed and they weren't fighting formal armies anymore, thus smaller and more adaptable units were called for to meet tactical demands. I'm not sure the issue of vexillations was as important as NN implies, rather that it reflected the size of the forces they were facing at the time (being raids of limited size more often than not). I strongly doubt vexillations, whose size varied according to need, were the basis of a new organisation, especially since they proved so difficult to keep track of.

 

The impression about the Roman advance being like a phalanx isn't even close to correct. The Goths moved faster and with the added suprise of an enveloping flank attack by cavalry, the somewhat disorganised Roman line folded up. And yes, poor leadership had a lot to do with it.

 

According to both Marcellinus and Zosimus, Sebastianus made use of small raiding forces composed of men recently recruited and more motivated to perform. He persisted with this strategy even during a political struggle for Valens good favour, and only changed his mind to support for a large battle (which he knew was a dodgy strategy with such ill-motivated troops) in order to survive politically and benefit from Valens "forthcoming victory" without waiting for Gratian to arrive and share the honour. In that respect, the ordines as you describe them represent exactly the sort of formation used by Sebastianus both in the initial stages of the counterattack against the Goths, and as the advance party that went ahead of the column and won an impressive victory at the River Maritza four days before the battle proper.

 

The above point about infantry doing well at Adrianople isn't supported by the facts. Valens had to spend time at Melanthia before he marched on the Goths making speeches to rouse the men to fight at all. Marcellinus, Zosimus, and Vegetius all refer to the poor level of manliness exhibited by Roman soldiers of the time. It's as well to point out that two-thirds of the Roman army were written off as casualties during the long hours of melee before nightfall allowed them to escape (although at least one unit, the Batavians, simply vanished)

[auxilia]

Wow, thanks for this in-depth view.

Ok, I may assume the infantry still used similar formation to that of the Principate. Perhaps, the single line array being more often than others (since the armies of the day were much smaller than those which deployed in the triplex acies - like Caesar's or Pompeii's).

As for the ordines, it remains difficult to say, except that in all probability they were used as an all-round multitask force.

 

The impression about the Roman advance being like a phalanx isn't even close to correct.

 

Why not? It seems quite probable....If the army was presumably in the shield-wall formation then it's movement and appearance alike really looked like the phalanx.

And we know the shield-wall was regularly used (Julian also used it at Strasbourg).

 

Now, since I've already mentioned this battle, and since you appear to be quite an expert , can you tell me what evidence we have for the battle formations used at Strasbourg against Alammani?

 

Regards

[barca]

Why not? It seems quite probable....If the army was presumably in the shield-wall formation then it's movement and appearance alike really looked like the phalanx.

And we know the shield-wall was regularly used (Julian also used it at Strasbourg).

 

Now, since I've already mentioned this battle, and since you appear to be quite an expert , can you tell me what evidence we have for the battle formations used at Strasbourg against Alammani?

 

Regards

 

Whatever their formation was, Julian provided much better leadership. His army seemed to have things under control.

They responded well to the attempted ambush, and when the front line was penetrated, they were able to mobilize their reserves.

 

These two battles were only a few years apart. I would think that the composition of the Roman armies at Strassburg and Adrianople were similar. The big difference was leadership.

[barca]

The above point about infantry doing well at Adrianople isn't supported by the facts. Valens had to spend time at Melanthia before he marched on the Goths making speeches to rouse the men to fight at all. Marcellinus, Zosimus, and Vegetius all refer to the poor level of manliness exhibited by Roman soldiers of the time. It's as well to point out that two-thirds of the Roman army were written off as casualties during the long hours of melee before nightfall allowed them to escape (although at least one unit, the Batavians, simply vanished)

 

This is a controversial and very important point. there are many who believe that the army that was annihilated at Adrianople was an elite force, which included the top military leaders of the Empire. It was hard enough to replace the troops, but even harder to replace the the leaders. There were perhaps hundred of thousands of additional troops in the empire, but only few of top quality.

 

I believe Vegetius was describing the status of the Roman Army after Adrianople.

 

Julius Caeser also had to give speeches to his men to rouse the to fight against Ariovistus.

[caldrail]

This is a controversial and very important point. there are many who believe that the army that was annihilated at Adrianople was an elite force, which included the top military leaders of the Empire.

Not controversial at all. There is no evidence that the legions present at Adrianople were in any way elite. Far from it, they represented a cross section of available troops, good or bad. The best of them had been taken ahead by Sebastianus as a raiding force ahead of the column.

 

It was hard enough to replace the troops, but even harder to replace the the leaders. There were perhaps hundred of thousands of additional troops in the empire, but only few of top quality.

You're assuming the generals were good at their jobs. Rome was never short of new recruits to the top job and any Emperor had people courting him for placement.

 

I believe Vegetius was describing the status of the Roman Army after Adrianople.

No, Vegetius wrote a manual in order to reform the legions he knew, and although the books were written later (ad390?), the condition of troops at that time was no different from those of ad378. Indeed, the debacle of Adrianople must have been very much in his mind.

 

Julius Caeser also had to give speeches to his men to rouse the to fight against Ariovistus.

So did just about any Roman commander before a battle if he had any sense and talent at public speaking. That's not the point. Rousing the men to do better is one thing. The efforts made by Valens at Melanthias were another. He wasn't speaking to his troops before the battle. He was exhorting them to get off their backsides and go to war, a speech he had top make more than once.

[Northern Neil]

Now, since I've already mentioned this battle, and since you appear to be quite an expert , can you tell me what evidence we have for the battle formations used at Strasbourg against Alammani?

 

Regards

Ammianus is our main primary source, and he was actually an officer in that battle.

[barca]

This is a controversial and very important point. there are many who believe that the army that was annihilated at Adrianople was an elite force, which included the top military leaders of the Empire.

Not controversial at all. There is no evidence that the legions present at Adrianople were in any way elite. Far from it, they represented a cross section of available troops, good or bad. The best of them had been taken ahead by Sebastianus as a raiding force ahead of the column.

 

Not controversial? It seems to me that it was a very controversial topic on the Adrianople thread. Is there any evidence that they were not elite? If you look back on some of the posts on the Adrianople thread, you'll find controversy.

 

For example, your friend sylla made numerous comments about the relative effectiveness of the late Roman Army

 

"My general impression (just that!) is that the general average performance of the armies of both the Romans and their enemies tended to progressively improve year after year, given the slow but real advance in tactics and weaponry. Besides, once the Roman conquest stopped (mainly for logistic reasons) and the Imperial borders became fixed, a permanent quasi-Darwinian selection of the Roman enemies took place there.

After the first phase, Roman armies ought to progressively increase as long as the emperors stubbornly tried to conquer even more and never retreat."

 

 

I believe his point was that the Roman Army was constantly evolving in order to adapt itself to changing conditions.

 

One also has to take into account that many of Fritigen's Goths had experience with the Roman military system. They had also been within the empire for about 2 years and had access to many resources, including the armory.

 

I agree that Sebastianus had great success with smaller missions, but didn't he subsequently join up with Valens' army at Adrianople?

[caldrail]

Not controversial? It seems to me that it was a very controversial topic on the Adrianople thread. Is there any evidence that they were not elite? If you look back on some of the posts on the Adrianople thread, you'll find controversy.

No, not really, just a disagreement. We began to argue over certain things, whereas a controversy is an already existing arguement

 

For example, your friend sylla made numerous comments about the relative effectiveness of the late Roman Army

 

"My general impression (just that!) is that the general average performance of the armies of both the Romans and their enemies tended to progressively improve year after year, given the slow but real advance in tactics and weaponry. Besides, once the Roman conquest stopped (mainly for logistic reasons) and the Imperial borders became fixed, a permanent quasi-Darwinian selection of the Roman enemies took place there.

After the first phase, Roman armies ought to progressively increase as long as the emperors stubbornly tried to conquer even more and never retreat."

 

I believe his point was that the Roman Army was constantly evolving in order to adapt itself to changing conditions.

Sylla has described normal campaigning experience, not an evolution toward a more efficent Roman army, which had remained pretty much the same for fifty years give or take a unit. In fact, the experienced troops billeted at Melanthias were less than keen to take to the field. Sebastianus chose the newer, more enthustiastic troops as his elite corps of raiders.

 

I agree that Sebastianus had great success with smaller missions, but didn't he subsequently join up with Valens' army at Adrianople?

Correct. That was because of politics, not elitism. Sebastianus had been personally chosen by Valens and summoned from Italy to serve as his senior commander in place of Trajan (who had built the walls to fend off the huns some years earlier). He was viewed as something of an upstart newcomer and there was considerable jealousy toward him, so he was constantly 'proving' himslef to Valens, and at one point Marcellinus mentions his letters praising his own success became a little too pompous - he'd overdone it. In order to find favour with Valens again, he supported the case for a quick battle, believing that Valens would be happier with sole credit for a victory (and as an arian emperor, Valens would be glad to avoid the need to share the triumph with his christian co-ruler Gratian, who'd been delayed by illness and Germanic attacks), and also that the Goths had been weakened enough to get away with such a move, especially since the Roman intelligence severly underestimated the gothic numbers.

Edited February 1, 2010 by caldrail

[auxilia]

Well, apparently any discussion about the roman battle tactics somehow ends in "Adrianople issue" (not only in this forum).

I don't mind, and I'm not criticizing you. However, as I see there are some difficult issues about the battle itself. Some of you talked about the roman army not being composed of elite troops if I got it correctly.

A few days ago I had started reading the Osprey's Campaign: Adrianople (I know that many don't like the Osprey books and consider them as not serious enough).

Early from the start an author made it clear: THE ROMAN ARMY WAS COMPOSED OF LARGELY ELITE CRACK TROOPS.

On the other hand he mentions that Valens was actually fighting in the east prior to Gothic's revolt so, naturally, one may wonder how elite the army deployed at Adrianople really was? Some elite legions and auxilia palatinae were definitely there but what about cavalry?

Overall, does it mean that only field army of Thrace was engaged or the praesentalis army was also there? In either case, it seems the army was quite elite that day.