Barbarization of the Roman army

[mr friendly guy]

Ok we knew during the later centuries the Roman empire had to adopt more and more barbarian troops into their legions. I just have a few questions on this.

1. What did they do to try and reverse this trend?

2. Why couldn't they succeed in reversing the trend? Or to put it another way, why did it become harder for the Romans to recruit native born Romans into the mix?

3. Was this just confined to the Western Roman Empire? Or did the Eastern empire also experience similar things, but to a lesser extent? In which case, why wasn't the Eastern Empire "barbarianised" to the same extent?

Hopefully when Thanas comes he goes easy on my ignorance.

[ray245]

I think some of my answers might not be as good as Thanas, but here goes.

1. Barbarians were employed in the Roman army ever since the Empire was founded. There were several attempts to recruit more Italians, but it never seems to have worked. The Romans did attempt to recruit more provincials as time went by, like the Illyrians for example.

2. It is much cheaper to enlist barbarians who were famous for their warlike ability than to train a roman citizen from scratch I supposed.

3. The Eastern Empire also employed a large amount of barbarians in their army, but the main issue is that they were never as reliant on federates troops as the Western Empire.

Despite that, there are a few works that actually dispute the so called Barbarisation of the Roman Army. I think you can refer to Hugh Elton's work for more information regarding this issue. He argued that the number of barbarians during the late Empire never really exceed the number of Romans in the army, at least till the later part of the fifth century.

[Spoonist]

I think you would need to define "later" to get a relevant answer, but the short one is: your basic premise is flawed.

[Thanas]

I think you would need to define "later" to get a relevant answer, but the short one is: your basic premise is flawed.

^This.


To elaborate:

I'll note that a lot of what I am about to say directly ties into my own research, so I will not go into too much detail (first rights issues and all that). If asked about specific points, I will try and answer in detail.

First of all, let us look at the historiography. History is not independent of the time period in which it is written. You will find that the "problem" of Barbarization mostly starts to gain acceptance in the 19th century in modern history and then is listed as a real problem. It then gained a lot of traction during the later 19th century, coinciding with a lot of military theorists claiming that the strength of a nation lies in the power of its own people, in the power of the citizenry of the predominant race fighting like true patriots for their nations.

So you can see a pretty easy pattern to emerge. Why did the Germans beat Varus at the saltus teutoburgiensis? Because they resisted foreign rule and defended their race from invaders. Why did the Romans fail? Because they hired Germans to do their job instead of being true racial patriots and the dastardly Germans or Romans stabbed each other in the back more than fighting invaders. You couple that with a period of Germanophobia on the side of French/English writers and of the hate of everybody west of the Rhine on the German/northern European side and you easily add up with a pretty racially charged and dominant theory accepted by everyone back then.

Suffice to say, the outlook has changed significantly since then.


Which leads us to the following questions:

Was there really Barbarization in the later Roman Empire?

This is the most important one and one that poses an interesting question of terminology. First of all, what is a barbar?

This is not as easy to answer. For example, when the Romans classified people, they did not do so on a racial basis. They did it on geographical and political association. One prominent example is the division into celts/gauls and Germans. When the Romans conquered the Rhine areas they arbitraily decided that everyone who lived on their side was a celt/gaul and everybody on the other side was a German. This was not based on any ethnic or racial trait. We know of the Romans relocating entire tribes, taking them from the German side and then settling them on the celtic side in the same year this distinction was made. We know that people who had been populating both sides of the river and considered themselves one tribe were split up or abitrarily classified as one or the other. That btw is why classifications such as "German tribe" or "Celtic tribe" can only denote political alignment at best and even then there are far too many examples to refute such a strong distinction.

What I am getting at here is that the tribes of antiquity were no united front, nor were allegiances a matter of ethnicity.

One rather easy way to go about this would be to say "everybody whose tribe does not owe direct fealty to Rome is a barbarian". Alright then, but how do you classify a Parthian, coming from the great city of Ctesiphon, being highly educated in several languages and having served in the Imperial bodyguard for 25 years and then having settled as a Veteran in Rome herself, fathering many children who then also served Rome? Is he still considered a Barbarian? (An analogy would be the many hispanic immigrants serving the US Army today - are they american or hispanic?) My point is, just because somebody is from a certain origin does not mean he is not a Roman. Heck, there were plenty of Roman Emperors who were not Roman citizens at first or were of "non-Roman" stock, even during the early 3rd century. For example, Maximinus Thrax was from Thrace, Phillippus Arabs was of originally Arabian decent and one of the most famous dynasty of Rome, the Severans, were descended from Northern African tribesmen. The Emperors Diocletian, Constantine and most of their successors were the descendants of the Illyrian tribes (who originally had to be subdued in year-long and bloody campaigns). Yet all of these somehow are thought of as typical Romans and they themselves believed them to be Romans. Yet while we accept that Emperors might be of barbarian descent and do not question their ancestry nor loyalty to Rome, somehow some people think that a lowly spearman living in Roman territory for most of his live after being recruited as a teenager does not count or has questionable allegiance.

The situation gets even more laughable when you consider that most of these tribes would have had over four-hundred years of direct Roman rule and cultural assimilation. They would have seen their tribesmen become Roman officials and maybe even Emperors for centuries. And then, during the reign of Caracalla, the Constitutio Antoniniana made everybody inside the territories of the Roman Empire de iure a Roman citizen. If you have been a citizen of a nation for over 200 years, how the heck are you not a Roman? It would be as preposterous as starting to count the tens of thousands of soldiers with polish names (and whose ancestors had been "German" citizens since Frederick the Great) who fought in the Wehrmacht not as Germans.

But, for the sake of argument, let us assume that anybody who came from a certain tribe was still a Barbarian. This leads us to the next Question:


How numerous were Barbarian units in reality?

This leads us right into a huge problem.

During the Principate (1st and 2nd centuries AD) the Roman Army was split into different categories. We had legions (recruited only from Roman citizens) and auxilia (split into units of Roman-citizens only and non-Romans). Of the over 350.000 troops per annum during that period, roughly half were non-Roman auxilia. This gives us 175.000 Barbarians.

OTOH, the late Roman army only had 65 auxilia palatina, which probably count as only 30-45.000 Barbarians in the field army. (There also are some auxillia units in the provincial armies but their relation to the other units is a minority one as well). We also have a large number of legions bearing barbarian names but that is also not an indicator they were barbarians.

So the main thing to take away from this is that there is the possibility of the army of the 1st and 2nd centuries might have had more non-Romans than the late Roman Army, proportionally speaking.

But it gets even worse for the pro-Barbarization people. Just because a unit has a barbarian name it is not filled with or recruited from Barbarians. Let us take a unit with a barbarian name. If one looks at the actual records of the soldiers and their names on the tombstones, it becomes clear that even in units called "Franks" or "Goths" the number of Barbarian names is in the vast minority, oscillating between 15-40%. This means that even so-called "barbarian" units were majorly filled with Romans. This gets even more serious the longer a unit has been in Roman service and the more it has been transferred. For example, the "Dacians" were at one time transported to Egypt. We have Papyri showing that in the same year they arrived, they started to recruit from the local population to replace losses. So now you have an Egyptian Roman serving in the "Dacian" unit. Quite frankly, the Romans did not care much for race. What they cared for were warm bodies marching under the standards. Their blood, looks or heritage were secondary to ability and willingness to fight.

So you can imagine how in the Late Roman Army, which existed for over 350 years in that command structure and organization, the name of a unit means squat in determining how "barbaric" they were, especially considering units were transferred from one end of the empire to the next. Heck, we know of one unit for example that was transferred from Italy to Gaul, to Britain, to the Balkans, to Persia and then back to Gaul. Within one decade, much of which was spent in hard fighting. I very much doubt this unit was anything but a mixed bag of many recruits from different ethnic heritages at the end of that - and that is supported by many sources. Even if we did not have those sources, the alternative would be pretty comical - imagine Roman officers saying "what, we lost over a third of our men in an ambush of these damned scots? Better wait over a year until the next gothic tribe shows up and provides recruits then. What do you mean, we go against the Germans next summer? Better do it understrength then, we must not dilute the blood of our beloved barbarians with those english Roman citizens. Don't worry, I am sure the Emperor will not totally have our heads when we fail to hold the line due to missing half of our men."

So to summarize - there is no evidence suggesting there was a barbarian majority. We do have evidence for a barbarian minority. But these would be quickly assimilated - Latin was taught from the beginning, simply due to the need of the men understanding orders and, you know, actually being able to talk to the new recruits from whatever province they were currently stationed in.

Which brings us too....


A barbarian is a barbarian is a barbarian...is a Roman?

Did somebody who served in the Roman Army consider himself a Barbarian or a Roman? For the enemy it was pretty clear. If you march under the Roman standard, you are a Roman no matter if you have blonde, black or red hair. But how did people born outside of Roman territories view themselves?

First of all, we have to note that for most Germans, Goths etc. the supremacy of Rome was not really in question. Most of them liked the Roman way of life. Rome usually provided a safe haven from trouble like blood feuds, civil war etc. There was a large history of Germans signing up in the Roman Army to escape precisely such troubles. Who do you think the loosing party in a civil war liked more - the people who burnt their homes and killed their friends or Rome which was all too willing to feed and cloth them, as well as pay them good money to fight against the people who killed their friends?

Even moreso, we have a large history of immigration into Roman territory. Even Augustus already accepted German settlers. And why wouldn't an Emperor do this? You could easily (re-)populate land, gain more taxpayers and manpower for the Army. The Romans at times even encouraged such immigration. And the "barbarians" largely accepted it. It is of note that even the goths who defeated the Romans at Adrianople were originally only begging for Land to be settled in and were willing to accept Roman overlordship until corrupt Roman officials starved them and tried to enslave them (or so the sources tell us. Huge shovel of salt here, but the overall point still stands). There is also no record of Germans being proportionally more disloyal. Heck, the ancient sources usually take great pains to mention the loyalty of the German Imperial Guard - which was more loyal than the "pure Roman" Praetorian Guard.

This brings us back to the individual men. Suppose you had served your time and were now a veteran. What choice would you make? Settle in Roman territory with full honours (and with your wife and kids), enjoy the comforts of civilization like free food for life, access to political life, daily hot baths in the Thermae or go back to cold, foresty Germany where chances are nobody really knows you anymore? If you were discharged in sunny Egypt, do you really want to take a trip across the entire known world to go back to the swamp? In fact we know of very few veterans who did not settle in Roman territory at the end of their service. I only know of one documented archeological evidence. The vast majority settled in Roman territory near their comrades in arms. We also know of cases where such veterans took up arms and defended Roman territory from invaders, even former tribesmen of theirs. At this point, I see little value in discounting the massive integration machine the Roman Army was in favor of calling people like that Barbarians.

And let us not forget that to become a Roman soldier provided a lot of upward mobility, provided one survived of course. Heck, your son which you fathered with a camp follower might even become emperor. Enticing possibilities for farm hands or farmers, right?

There is a problem however when considering Barbarian nobility. Essentially, many of these guys already had a "Roman" education even while being barbarian. They mostly would be speaking Latin already. Still, even a lot of those became Roman officers due to political issues at home or because the rewards were still substantial. For example, Nevitta, a Frank, became consul and I am sure I do not have to list the long list of dominant "barbarian" Generals. However, most of those were already romanized to the core and had nothing but the goal of marrying into noble Roman families or the Imperial household.

Anti-German backlash and loyalty trouble only seemed to have occurred when whole tribes were permitted to keep their political structure intact in the fifth century and Germanic tribes became more of a widespread problem. However, note that this is only occurring 1.5 centuries after "barbarization" was already in full swing and the most loyal General of that period was of Barbarian Origin (Stilicho). In fact, Barbarian officers and men tried to become as Roman as possible even during that time.

So IMO the whole issue of Barbarization is a non-issue. The Romans clearly thought there were no large problems to recruiting Barbarians, who often proved themselves to be loyal, dependable and elite soldiers. And the Barbarians themselves were oftentimes all too glad to be Romans, and to be accepted as such.

Two salient examples: When Julian defeated the Franks, his elite regiments were commanded by Nevitta, a Frank himself. He became Consul of Rome. When the Alamanni, a coalition of germanic tribes, invaded Gaul in 365, they were opposed by the Roman General Dagalaifus, who himself was a "German". He became Consul of Rome the following year. Were they acting as Barbarians or as a Roman officers? In both cases Germans made up a portion of the army that beat back the German invaders. Were they acting as Roman soldiers or Barbarians? The answer should be clear.





Now, to the specific questions:

1. What did they do to try and reverse this trend?

Why would they do so, considering that "barbarians" had been recruited by the empire for over 400 years and some of their best soldiers would be Barbarians? Also note that the Romans had manpower issues.

2. Why couldn't they succeed in reversing the trend? Or to put it another way, why did it become harder for the Romans to recruit native born Romans into the mix?

- There is no evidence that the Romans really had to
- The Romans had very high recruiting standards resulting in less than 2% of the Empire's population being able to meet those. These standards were lowered in the later centuries but serving as a soldier was more attractive for the frontier armies, not the field armies (bad risk/reward ratio, service far away from home, high mortality, better chances for economic advancement in the local economies). As a result Barbarians became more important to the field armies as they were able to provide more recruits - and even better motivated ones.
- Every recruit you hire and romanize is one less Barbarian to worry about. If he has healthy sons, you even get bonus soldiers out of it.

3. Was this just confined to the Western Roman Empire? Or did the Eastern empire also experience similar things, but to a lesser extent? In which case, why wasn't the Eastern Empire "barbarianised" to the same extent?

There is no evidence for lesser or higher barbarization on part of the Eastern Empire, except for the last fifty years of the Western roman empire. During that period the following happened:
- The regular roman Army structure pretty much collapsed in the west after the death of Aetius 454 and the events that followed it.
- Barbarian tribes were now recruited wholesale, under their own commanders, unit structure and laws. This means the process of integration was not happening that well anymore, though mixed units still existed. In the east only mixed units might have been recruited and in the west they might still have been in the majority. But besides these there were also the germanic tribes recruited wholesale, which were much harder to command and often were a pest.
- As the entire western Empire was overrun by Germans, central Roman authority disappeared and so did the Roman control and Roman Army. The East was not overrun, ergo it maintained its previous structure.

However, please note that we are talking about a very small window of collapse when compared to the centuries of success (20+ years compared to over 400 years of success of hiring "barbarians"). But this window is still very large - consider that even with "barbarians" being predominant the Romans still managed to survive for 20 years. Which is a very long time to survive as an Empire under constant attacks. No other empire in European history has had a total collapse of the central structure and still managed to survive for over 20 years, in no small part due to Barbarians fighting for the empire.

I hope this answers the questions - I realize the massive essay above might be tl,dr but I felt it necessary to clarify a few things.

[mr friendly guy]

I think you would need to define "later" to get a relevant answer, but the short one is: your basic premise is flawed.

I was thinking mainly 4th and 5th centuries. I know the term seems loaded to me even as historians used that term. But for my purposes I think of it as non Roman people who while fighting in Rome's armies, did so more akin to mercenaries rather than as Roman soldiers, with their own standards, weapons, "uniforms" etc.


@Thanas.
Thanks. You did answer my questions and made me realise the problem I was thinking of is less so to do with "barbarians" in the Roman legions, but failure to integrate them. Which ultimately caused problems down the track for them.

[Thanas]

@Thanas.
Thanks. You did answer my questions and made me realise the problem I was thinking of is less so to do with "barbarians" in the Roman legions, but failure to integrate them. Which ultimately caused problems down the track for them.

You missed the point. Integration worked just fine for over 450 years.

It did not work when the empire completely collapsed, but it is hard to say what role failed integration played in that. Probably less of a role than the Emperor murdering his best general and causing riots which cause a third of the army to desert.

[ray245]

Just a question to Thanas.

Are you going to publish your research in a journal, or are you publishing it as a monograph?

[Thanas]

That depends if it gets published or whether I will keep it more of a basis to expand on in a larger monograph. Most likely a few articles at first on tangential issues followed by a monograph.

[mr friendly guy]

You missed the point. Integration worked just fine for over 450 years.

It did not work when the empire completely collapsed, but it is hard to say what role failed integration played in that. Probably less of a role than the Emperor murdering his best general and causing riots which cause a third of the army to desert.

You mean the killing of Stilicho?

[Thanas]

Stilicho is another good example of this. I was referring to Aetius though, who was the last General who managed to bring some semblance of stability to the frontiers.

[Rabid]

Let us take a unit with a barbarian name. If one looks at the actual records of the soldiers and their names on the tombstones, it becomes clear that even in units called "Franks" or "Goths" the number of Barbarian names is in the vast minority, oscillating between 15-40%. This means that even so-called "barbarian" units were majorly filled with Romans.

As an history noob with absolutely no knowledge on the matter, I have to ask : what are the odds that it could have been an usual practice for "barbarian" recruits to Romanize their names ?

I ask not to ignore or criticize your main point, just to know from someone who has studied the matter, as it is picking my curiosity.

[Thanas]

No, in fact it is a legitimate question. It is also the first thing one looks at.

But let us take your example. You think they retained a barbarian identity and language, but somehow - after, under this model, being recruited as a group of barbarians - the majority decides to romanize their names? For what end? If they were in the majority, why would they do that? What could have made them do that?

And of course, there is the counterargument that when the highest officers in the entire empire felt no need to change their name, why would the grunts do that? I mean, Dagalaifus is not a roman name. Neither is Nevitta. Nor are Arbogastes, Andragathius, Ricimer, Gundobad, ovida, Onoulphus, Richomeres, Aspar....

This is the group who had the most incentive to change their name as they lived in the highest social circles of the empire. But to be honest, the Romans did not care about the name of a person by then. Heck, when the "barbarian" officers married into distinguished families, what did they do? They simply combined the names, Barbarian and Roman. See just one example of that. There were people who still viewed them as foreigners but apparently that still was not enough to convince them to change their name.

So why would these people who called each other by barbarian names all their lives suddenly change the name? Besides, what is the point of, in a 500 man unit, three quarters suddenly switching their names to Roman but the other guarter does not?

I cannot deny that some changing most likely occurred due to a desire to assimilate. However if there was such a desire it defeats the assumption of barbarization immediately, as the theory of barbarization relies upon barbarians causing damage due to unwillingness to assimilate. If people want to be more Romans than the Romans so to speak, that defeats the whole point.

In fact, if we had evidence of name switching the whole barbarization angle would have died out long ago. There is an exception: when granted special privileges and Roman citizenship, it was not uncommon for barbarians to add Flavius to their name, showing the favor of the Flavians (Constantine dynasty was called the second flavian dynasty). However, Romans did the same and this is not the name switching we are talking here, as Dagalaifus would still be Flavius Dagalaifus.

[Rabid]

I see.

Thanks for this instructive answer.

[mr friendly guy]

Thanas, why did the Roman army have manpower issues, particularly in the 5th century? At the battle of Chalons, Aetius had to recruit visigoths who fought under their own standard to fight the Huns. I am particularly interested in why they couldn't make up the numbers from Italy? Was the empire simply too vast at that point, even with the Germanic soldiers in their army (who I presumed were citizens of Rome and not mercenaries).

BTW - I have heard it said, I think the quote was from Gibbons, that the Empire had lost its martial vigour by this stage of history. What is your view on this?

[Knife]

Not to assault Thanas with questions, but...

Are you saying, or implying, that Legions with barbarian names mentioned in your post, could be seen more like naming units after Roman states/provinces or even area's of contention? Something akin to the US Navy naming battleships or subs after US States or cities? I find that fascinating.

[Thanas]

Not to assault Thanas with questions, but...

Are you saying, or implying, that Legions with barbarian names mentioned in your post, could be seen more like naming units after Roman states/provinces or even area's of contention? Something akin to the US Navy naming battleships or subs after US States or cities? I find that fascinating.

Legions were named after the following things:
- Provinces from where they were recruited
- The gods
- The gods of the Emperors
- The Emperors
- Their parent units
- (maybe) the barbarian tribes they were recruited from - assuming we accept barbarians serving in legions - they might still have been recruited from Roman citizens only.

Naming units after provinces or after conquered enemies or enemies they were supposed to defeat had been done by the Romans ever since the Republic. That is nothing new. Witness, for example, Legio I Italica, or Legio IIII (not a typo) Scythica, or Legio I Parthica.

Thanas, why did the Roman army have manpower issues, particularly in the 5th century?

Woah. Nobody can really claim the army as a whole had manpower issues. The evidence for that is very little. Until the whole system starts to collapse rapidly after the Death of Aetius, one can still claim that demands were met.

First of all, by all indications service in the immobile frontier armies was not that unattractive. On the other hand, we have people begging not to be sent to the field army. The reasons for that is simple - service far abroad and a high risk of death, given the field army was pretty much playing fire brigade all over the empire. How would you like to fight 18 years without a pause? And how high do you think your chances are of dieing? There is probably a fair chance of you surviving until retirement, but do you feel comfortable taking that 40-50% chance of dieing? (Note that ancient combat pretty much ensued that when things went wrong, nearly the whole unit was lost. OTOH, if things went right, there were little to no casualties). Service abroad also rips you out of the local economy. Still, I am not prepared to say service in the army was per se not attractive, mainly that it was less attractive than in the previous centuries where you could see peace for decades. Heck, a legionary in the 2nd century AD had a pretty good chance of retiring without ever seeing combat.

Then there are the high recruiting standards of the army. When you only accept the top three % of the population as fit for service (BTW, this is also why the topos of stronger barbarians smashing smaller Romans who only prevail due to discipline is just that, a topos - on average the Romans were stronger, fitter and better trained) then you only need a small fraction of that not enlisting to have a manpower shortage.

The Romans had mandatory registration and mandatory service later on. It is not clear if there is any evidence that it did not manage to satisfy demand.

No, the reasons for hiring the barbarians were IMO (and until it gets published just my opinion) much different - the Barbarians were more motivated to fight, more loyal than the Roman troops and did not take away useful farmhands or tax payers. If you have to drap people from their farms to serve under threat of punishment or you can just hire somebody from across the River who actually wants to fight, who do you take?

Also, the Romans used hiring barbarians as a method to deprive enemy tribes of their manpower. This is why defeated tribes regularly had to give a portion of their army to the Romans in the peace treaty. You get to take the enemies best warriors and if you ship them to the other end of the empire they can cause no problems.

So the question IMO is not whether the Romans needed to hire barbarians, but whether it was not the best scenario for them.

At the battle of Chalons, Aetius had to recruit visigoths who fought under their own standard to fight the Huns.

Given that they were not recruited, but allies, this is not really saying anything. Do you expect the British in Afghanistan to fight under US standards?

I am particularly interested in why they couldn't make up the numbers from Italy? Was the empire simply too vast at that point, even with the Germanic soldiers in their army (who I presumed were citizens of Rome and not mercenaries).

See above.

BTW - I have heard it said, I think the quote was from Gibbons, that the Empire had lost its martial vigour by this stage of history. What is your view on this?

An obsolete point of view not supported by any of the evidence. Gibbon merely wanted to show the history of the empire as one which lost its martial vigour due to christianity's weakling influence.

[Simon_Jester]

I'm trying to piece together a non-obsolete point of view from this, Thanas; let me see if I follow you.

The Imperial military system basically worked, with varying degrees of victory and defeat, up to and past the year 400 AD. Things started to fall apart towards the very end of the Empire, particularly with the death of Aetius, because... what? What, exactly, went wrong?

If I'm following you, then the answer, as best I can summarize it, is that by the middle of the fifth century, the Empire was awash in barbarian nations. Many of them had been invited into the Empire intact and under their own native leadership. Obviously, that was not sustainable- invite someone like the Franks or the Visigoths into one of your provinces and it stops being your province.

Aetius spent his career running around trying to put out the fires created by this policy, with some success, but to a real extent he was relying on the barbarians inside the borders to defeat the ones outside the borders. This is very different from the longstanding policy of recruiting barbarians into the legions. It's like the difference between the US Army having Mexican immigrants in its ranks and having entire divisions of the Mexican army go fight its wars for it.

So there was this policy of bringing in barbarian tribes fully intact. And once Aetius was out of the picture, without his skill at binding up the wounds, the strength of the Empire bled out quickly. Britain, North Africa, Gaul, and Hispania were lost, dissolved into regions ruled by the various tribes; finally, the Goths came in and finished off the western Empire by taking over the Italian heartland.

Do I have that right?

Assuming I do, the next logical question comes from taking a step back: why did the policy change in the first place? Why did fifth century emperors actively invite barbarian tribes into the Empire, when fourth century emperors did not? Was it just a disastrous mistake by a single stupid emperor looking for support? Or was it an indirect consequence of some other problem that had weakened the Empire by 400 AD?

[ray245]

You might want to look up the battle of Adrianople and the subsequent event that followed.

[Iosef Cross]

I think that the so called barbarisation of the Roman army was a consequence of the general economic decline of classical civilization. This process started around the mid 2nd century, perhaps earlier, perhaps later, depending on the set of archaeological data used. However by the 4-5th centuries the decline of classical civilization was very clear:


*the X axis are the centuries
*the Y axis are data indexed as 100 for the first century

Sources for the data:
Mediterranean Shipwrecks, Water Lifting Devices, Fish Salting Factory Capacity & Population density in Central Italy (in the albegna valley) are taken from Quantifying the Roman Economy, Alan Bowman and Andrew Wilson
Lead Pollution is taken from Social Development, Ian Morris
Copper Pollution is from Anthropogenic Air Pollution in Ancient Times (www2.sci.u-szeged.hu/eghajlattan/.../005-015.pd)

Notice that levels of copper pollution declined by a smaller extent than other factors because China was also a strong producer of copper (while they didn't produce much lead, since lead was a by product of silver smelting and the Romans were the only significant producers of silver in the world), so if the Roman Empire produced 90% of the world's copper while China produced the other 10%, if the Roman output fell by 95% while Chinese output stagnated the world's output of copper would decline by 84.5%, which was the decline in copper emissions from the 1st to the 8th centuries.

So a process called "barbarization" can mean a decline in the general homogeneity of the culture of the Roman Empire, caused by the collapse of economic integration. This was reflected in the army. The Late Roman Army was less homogeneus than the Early Roman Army, and perhaps starting to look similar to the armies of the Achaemenid Persian Empire in the regard.

The process of heterogeneization of the culture of the Mediterranean World from the Early Empire onwards was the inverse of the process of cultural homogeneization that happened during the 8th though 1st centuries BC, from the Archaic to the Early Empire, where hellenization and romanization acted to create a mostly unified classical culture over a massive territory. So if the rise of classical civilization gave us the legions, uniform in equipment, wages and training from Britain to Egypt, it's decline gave us heterogeneus "barbarian" armies.

[Thanas]

All your data is either insignificant or outdated. And your assumptions show why you got that title.

[Elfdart]

No, the reasons for hiring the barbarians were IMO (and until it gets published just my opinion) much different - the Barbarians were more motivated to fight, more loyal than the Roman troops and did not take away useful farmhands or tax payers. If you have to drap people from their farms to serve under threat of punishment or you can just hire somebody from across the River who actually wants to fight, who do you take?

Seems logical, especially since the Byzantines did something quite similar when they formed the Varangian Guard.

By the way: barbarians were to the Roman Army what rednecks have always been to the US Army?

Also, the Romans used hiring barbarians as a method to deprive enemy tribes of their manpower. This is why defeated tribes regularly had to give a portion of their army to the Romans in the peace treaty. You get to take the enemies best warriors and if you ship them to the other end of the empire they can cause no problems.

Wasn't it also a way of making them (the leaders at least) more Roman?