The Dacians: Rome\'s Greatest Enemy?

[Decimus Brutius Varus]

"Protochronism" is a term that was spread up (with a negative meaning) after 1990 due to mediatic involvement of George Soros fundations. This Soros guy is bend to spread the "multiculturalism" ideas in Eastern Europe (or whatever) and to supress anything related with "nationalism". Its just a PR campaign with the intend to "rewrite" the history so things that may disturb those ideas are branded as "negative", misinterpreted or purposedly ignored. A kind of "damnatio memoriae" of the past but which have success to gullible or less knowledgeable people

Wait, you didn't just take the "blame it on the Jew" approach, did you? Fair warning, it definitely came off as anti-Semitic.

Speaking of which, who wants to vote that the Judeans were a greater 1st century enemy to Rome than the Dacians? I think I could make a fairly spirited argument!

[Flavivs Aetivs]

Israel has always been a spirited country, but I dont think they were much of a threat. I'd say the Parthians remained at the top, and overall I think it's a Tie between the Sassanid Persians and the Hunnic Empire.

Also, I personally don't like the concept of nationalism, but I guess that's because I'm from a highly multicultural nation. Dacia has always been a cultural melting pot. But that's a different discussion and off-topic from this thread

[Frostwulf]

Back to the subject at hand:

In retrospect of all of Rome's enemies, it seems to me that the Dacians, under Decebalus, were Rome's most potent enemies-especially in Europe.

At a certain time this was true, but not during Domitians reign but rather at the end of his reign.

This is reinforced by the fact that very few of Rome's enemies had the capability to completely dismantle a legion in open battle (the battle ofTeutoberg forest and the attck on the ninth were ambushes).

Just going with the "Germani" you had multiple defeats inflicted upon the Romans by this macro grouping. Starting with the TCA(Teutons,Cimbri,Ambrones), the Sugambri and the Lolian disaster(Romans lost a legion in set battle),the Frisian revolt, and even during Domitians time you have the Marcomanni crushing Domitians army(in the 160's the Marcomanni also killed in a set battle over 20k Roman soldiers), hence the hasty treaty with Decebalus.

During Domitian's Dacian Wars, The Dacians annhialated Legio V Alaude, 2(?) Cohorts of Praetorian Guard, killed the praetorian Prefect, Cornelius Fuscus and the Moseian governor Oppius Sabinus (in a seperate incident).

Both Sabinus and Fuscus were killed by ambush and as for Alaude, they perished in with Fuscus.

The only reason that the Dacians didn't overrun eastern Europe was because V Macedonia(?) won a Pyrric victory against the Dacians, And Domition packed the border with the I and II Audrix.

Where did that come from?

In Addition to this, we know that the Dacians had extremely advanced fortifications, were well armed, more numerous, well led, and highly motivated.

Agreed!

They were also the only enemy that got tribute from the Romans.

I guess this depends on what you consider tribute, as Rome paid off many peoples. But as far as this being of Decebalus doing you need to again look to both the Marcomanni and then to Saturninus for this happening.But here is what happened and why Decebalus received tribute:
1. Domitian moved his troops to war upon the Germans(The Marcomanni were seen more as a threat at this time by the Romans).
2. The Dacians attack across the weakened frontier, they surprise the Romans and kill the governor Sabinus and allot of his soldiers.
3. Fuscus start clearing Moesia of Dacians, then crosses over to Dacia, is overwhelmed(ambushed) and defeated.
4. Tettius Julianus(with around 4 legions) is sent in and defeats the Dacians at Tapae.
5. Domitian loses heavily to the Marcomanni.
6. Saturninus rebels and Domitian is forced into an unfavorable treaty.

And remember, it took ten legions and an unknown number of auxillary cohorts, under the personal direction of Trajan, to take down Dacia's small kingdom.

This number varies from as low as 30,000 to as high as 150,000. Most of the authors mention Dacia as a local threat and not much else. As far as Dacia being a small kingdom, that also is under interpretation. Numbers for available soldiers run from 40,000(Oltean) to 250,000(Strobel,Schmitz and Blanchard).
I have debated both of these subjects with diegis and if need be I can post a link to those posts which do provide professional opinion.

[diegis]

"Protochronism" is a term that was spread up (with a negative meaning) after 1990 due to mediatic involvement of George Soros fundations. This Soros guy is bend to spread the "multiculturalism" ideas in Eastern Europe (or whatever) and to supress anything related with "nationalism". Its just a PR campaign with the intend to "rewrite" the history so things that may disturb those ideas are branded as "negative", misinterpreted or purposedly ignored. A kind of "damnatio memoriae" of the past but which have success to gullible or less knowledgeable people

Wait, you didn't just take the "blame it on the Jew" approach, did you? Fair warning, it definitely came off as anti-Semitic.

Speaking of which, who wants to vote that the Judeans were a greater 1st century enemy to Rome than the Dacians? I think I could make a fairly spirited argument!

Good God, now if i criticize a person who happen to have Jewish roots i am anti-Semitic? Are you for real?
I may expect to be accused i am a bloody racist Nazi if i say that Jews was defeated by Romans and many was killed, enslaved or deported? Is this the line you want to go in proving "that the Judeans were a greater 1st century enemy to Rome"?

[diegis]

Back to the subject at hand:
Both Sabinus and Fuscus were killed by ambush and as for Alaude, they perished in with Fuscus.

Hmm, from where do you get this ambush part? Sabinus was killed during battles in Roman province Moesia, and Fuscus was maybe "surprised" by the arrangement of Dacian battle formations, because is hard tot alk about an ambush against 5-6 legions + auxiliar troops.
The very few writings preserved today talk about battles, not ambushes, and about "lost legions" and they even talk about "keeping silence about the number of slains" suffered by Romans

Where did that come from?

It is probably reffering to campaign from Moesia in 85/86. Dacians/Getae in Burebista time especially has run over Illyria and Macedonia (both Roman provinces at that time). Ceaser himself (which was governor of Iliria) prefered to close his eyes over that and turn around and go for an easier prey, the Gauls and Germans/Suebi of Ariovist

They were also the only enemy that got tribute from the Romans.

I guess this depends on what you consider tribute, as Rome paid off many peoples. But as far as this being of Decebalus doing you need to again look to both the Marcomanni and then to Saturninus for this happening.But here is what happened and why Decebalus received tribute:
1. Domitian moved his troops to war upon the Germans(The Marcomanni were seen more as a threat at this time by the Romans).
2. The Dacians attack across the weakened frontier, they surprise the Romans and kill the governor Sabinus and allot of his soldiers.
3. Fuscus start clearing Moesia of Dacians, then crosses over to Dacia, is overwhelmed(ambushed) and defeated.
4. Tettius Julianus(with around 4 legions) is sent in and defeats the Dacians at Tapae.
5. Domitian loses heavily to the Marcomanni.
6. Saturninus rebels and Domitian is forced into an unfavorable treaty.

The main fact who show that Romans paid a tribute to Dacians is that Decebalus kept the standards captured (including the Pretorian Guard standard), as well parts of prisoners and war machines captured. This beside getting lots of money and receiving engineers send by Domitian and even desertors from Roman army who took refuge in Dacia

The fact he keep those standards show alone who was the winner and how big was the humiliation for Romans.

About your points
1- where is said that? Marcomani was Roman clients back then and Domitian had some war against Chatti as far as i know, years before wars with Dacians. By the time of Dacian attack Romans was on the way to conquer Caledonia, with Agricola sailing around there after defeating the Caledonians in battle. Actually i think CAledonia was spared for occupation at that moment precisely because Dacian attack, as Agricola was called back imediatly after that

2- Dacians attacked because Domitian ended a previous agreement to pay them. It was a punishment expedition

3- correct in much part, except the ambush

4- correct, with the mention that Tettius Iulianus retreated imediatly after the battle, way before any problems with Quadi, Marcomani or Saturninus. Which mean that Romans losses was too big to keep going and he was afraid to do that. Dio Cassius mention a trick of Decebalus, with trees cut at the height of a man and with armors, helmets, shields and weapons put on them to look as an army from the distance. When Romans saw that they was afraid to advance, turn around and leave Dacia, but not sure how correct was that

5- Domitian didnt lost that heavily, actually Marcomani send two envoys before, ask him for peace and tell him that they obey. Domitian however kill the emisaries every time, which produced outrage among Marcomani and Quadi who decided to fight back.
The reason Domitian wanted to beat them (they was Roman clients) was that they didnt want to participate in the war against Dacians. They wasnt back then of any threat for the Roman empire, or its frontiers.

6- Saturninus rebellion was put down before Domitian even reach there, in 89 both Marcomani and Saturninus problems was resolved, yet Domitian was afraid to cut again the payment of tribute for Dacians, or even to ask for those lost standards. And it was about Pretorian Guard standard, the most important of Roman army, representing the elite unit who guard the emperor himself.

This number varies from as low as 30,000 to as high as 150,000. Most
of the authors mention Dacia as a local threat and not much else. As far as Dacia being a small kingdom, that also is under interpretation. Numbers for available soldiers run from 40,000(Oltean) to 250,000(Strobel,Schmitz and Blanchard).
I have debated both of these subjects with diegis and if need be I can post a link to those posts which do provide professional opinion.

The numbers are unclear indeed, for Dacians. About the number of Roman troops, thats a bit more clear (even not without debate) and they are from 75,000 up to 175,000. I saw even 200,000 (but this sound a little too big even for me) as Trajan used as well a lot of iregular troops, a kind of mercenaries raised just for this wars, like Germans who appear on the Column (possible used as "cannon fodder" as they appear fighting half naked and armed just with clubs from what i remember). Not sure where you saw 30,000 for Trajan army?

The estimates for Dacian army goes from 40,000 to 100,000. 250,000 is the supposed number of availlable soldiers in Dacia, nobody say that they was all gathered in the army or fight all in any circumstances.
Is like saying that Roman army had a capacity of 500,000 soldiers but this doesn't mean they was all in Dacia at the battle of Tapae

[Christian]

I'm a rather perplexed by this statement below - the second sentence onwards:

Dacians was arguably the most respected enemies at Rome. They was the only ones that was represented in statues (quite lots of them). But none of those statues show Dacians as prisoners or in chains or dying.

It's so completely and demonstrably wrong - diegis, why claim it?

[Flavivs Aetivs]

I would argue that spread out over multiple fronts the romans could have fielded around 100,000 for the campaign, but as one concentrated fighting force they couldn't have. Disease, Logistical supply, and other factors would make that highly implausible. Same applies to the dacians, who didn't have nearly the capabilities of the Romans.

[Decimus Brutius Varus]

Israel has always been a spirited country, but I dont think they were much of a threat. I'd say the Parthians remained at the top, and overall I think it's a Tie between the Sassanid Persians and the Hunnic Empire.

I say simply because they annihilated the Syrian army and held up fairly well (better than anyone before them, perhaps) to Roman sieges (Jerusalem, Masada). I just wanted to stir the pot, so to speak.

[Frostwulf]

Hmm, from where do you get this ambush part? Sabinus was killed during battles in Roman province Moesia, and Fuscus was maybe "surprised" by the arrangement of Dacian battle formations, because is hard tot alk about an ambush against 5-6 legions + auxiliar troops.
The very few writings preserved today talk about battles, not ambushes, and about "lost legions" and they even talk about "keeping silence about the number of slains" suffered by Romans

For the surprise:

At the end of 85 or the beginning of 86 AD,[1] the Dacian king Duras ordered his troops to attack the Roman province of Moesia on the southern course of the Danube river. The Dacian army was led by Diurpaneus, the later king Decebalus.[2] It seems that Romans were caught by surprise, since the governor Oppius Sabinus and a legion, probably the V Alaudae, were annihilated.[1]

http://en.wikipedia.org/wiki/Domitian%27s_Dacian_War
And this:

It would seem that the outbreak of the Dacian war took the Romans by surprise. The first attack on Moesia at the end of 85 or the beginning of 86 was so unexpected that the governor, Oppius Sabinus, together with a legion, probably V Alaulade, was defeated. Pg.82

Perhaps it was meant another way, but that is the way I took it.

For Fuscus and surprise:
http://www.ancientlibrary.com/smith-bio/1300.html
see pg. 192
http://books.google.ro/books?id=swDMiX4_...&q&f=false
see pg. 11

In the same year (86), after the initial success against Dacians, Cornelius Fuscus crossed the Danube. However, his army was ambushed and destroyed while Fuscus himself died in the battle.[3] According to E.T. Salmon and other historians, this was the battle where Legio V Alaudae was annihilated.[6] At any case, this legion subsequently disappeared from the Roman army list.[4]

http://en.wikipedia.org/wiki/Domitian%27s_Dacian_War

As far as Fuscus and 5-6 legions see same wikipedia article and those addressed, and this:

Perhaps flushed with his recent victory, the desire for further glory and the need to challenge Decebalus in battle pushed Fuscus to adopt the bolder course of action. To postpone battle would only delay the inevitable and permit Decebalus and his army to grow stronger. Fuscus assembled the V Alaude and the VII Claudia with perhaps the millarian cohorts of the IIII Flavia and I Adiutrix legions. To this force was added a small collection of auxilia. Evidence for auxilia in Dacia prior to 93 CE was scant given that most auxiliary units were transferred to Moesia only after the destruction of the XXI Rapax in 92 CE. Most of the auxilia in Moesia during Fuscus command served in the fort system in Dobrogea. Given the scarcity of auxilia Fuscus placed the V Alaude reinforced with the millarian cohorts of the IIII Flavia and I Adiutrix legions at the forefront of the column.

This is not 5-6 legions but maybe over 2, maybe considering the casualties these legions took.

Ceaser himself (which was governor of Iliria) prefered to close his eyes over that and turn around and go for an easier prey, the Gauls and Germans/Suebi of Ariovist

Or what all the historians I read say, that the Helvetii provided opportunity first, thereby preventing Caesars crushing of Dacia. You say he was afraid, yet he made preparations for their destruction right after the civil war.

1- where is said that? Marcomani was Roman clients back then and Domitian had some war against Chatti as far as i know, years before wars with Dacians. By the time of Dacian attack Romans was on the way to conquer Caledonia, with Agricola sailing around there after defeating the Caledonians in battle. Actually i think CAledonia was spared for occupation at that moment precisely because Dacian attack, as Agricola was called back imediatly after that

This:

He remained content, however, with one Dacian victory and immediately moved against another enemy, the Germans on the Danube. There is much to support the view that in the early 80s he had already been mobilizing against them; at that time he was already concentrating troops on the German Danube front, and it is not out of the question that the sudden appearance of three legions in Moesia in 86 was made possible by previous preparations for an assault on the Germans. The Dacian attack came as such a surprise to the Romans simply because the government was concentrating all its attention on the Germans. This had probably not escaped the notice of Decebalus. Pg.83

The war against the Chatti was in 82-83.

2- Dacians attacked because Domitian ended a previous agreement to pay them. It was a punishment expedition

3- correct in much part, except the ambush

4- correct, with the mention that Tettius Iulianus retreated imediatly after the battle, way before any problems with Quadi, Marcomani or Saturninus. Which mean that Romans losses was too big to keep going and he was afraid to do that. Dio Cassius mention a trick of Decebalus, with trees cut at the height of a man and with armors, helmets, shields and weapons put on them to look as an army from the distance. When Romans saw that they was afraid to advance, turn around and leave Dacia, but not sure how correct was that

I don't know about number 2, where did you get that information from?
3. See what was written above about ambush.
4. Not according to this:

Facing new problems on the northern and Pannonian Danube, Domitian could not solve the Dacian problem militarily by a victory that could make up for the two previous defeats and dissolve the Dacians’ unity, for an easier defense of Moesia. That is why he accepted Decebalus’ peace offer. Although Decebalus had won two victories, he was aware that a methodical Roman campaign, led by a professional like L. Tettius Julianus could not result in but his downfall. Pg.194-195

It is suggested that Julianus based himself at Viminacium when the time came to enter Dacia, since this is the gateway to the heartland, leading to the Dacian stronghold of Sarmizegethusa. This would lead him across the Banat- on the same route that Trajan followed in 101- leading to Tapae on the south-western edge of Transylvania, where the final battle was fought, a victory for the Romans. Little is known of the details of the preliminaries of the battle, or the troops involved. The Dacians were soundly defeated, but not eradicated. Dio describes how Vezinas, next in rank to Decebalus, pretended to be dead and later escaped. The story continues with the bizarre description of how Decebalus cut down trees and placed armour on the remaining stumps so that the Romans would think they were warriors and withdraw, instead of attacking the royal residence. Nothing more is known of the fighting, save the decorations won by a centurion of II Adiutrix may have been won during the campaign. The battle of Tapae may have been fought too late in the year to pursue the Dacians right into their capital. Domitian had recieved two further Imperial salutations by September 88, and another by October, reaching a total of 17. Julianus probably thought it prudent to avoid pursuing the campaign in hostile territory in winter and Domitian may have approved or advocated plans for another attack beginning in the following spring. But before the victory could be followed up and the coup de grace delivered, another rather more immediate problem had arisen. Pg.100

Shortly after, news reached Rome of Julianus’ victory over the Dacians at Tapae, only the lateness of the season preventing him from pressing home the advantage. Domitian took his fifteenth and sixteenth imperial salutations at the end of the year, and with the gateway to the Dacian Basileion stormed, could reasonably look forward that winter to outright victory in the coming season - only to be distracted from achieving his aims once again, this time by an insurrection fomented by L. Antoninus Saturninus, army commander of Moguntiacum (Mainz) and Upper Germany. Pg.29

5- Domitian didnt lost that heavily, actually Marcomani send two envoys before, ask him for peace and tell him that they obey. Domitian however kill the emisaries every time, which produced outrage among Marcomani and Quadi who decided to fight back.
The reason Domitian wanted to beat them (they was Roman clients) was that they didnt want to participate in the war against Dacians. They wasnt back then of any threat for the Roman empire, or its frontiers.

He lost and had to sue for peace with Decebalus, and also the Marcomanni did attack in 92.

After two Roman generals had suffered serious reverses, a third, Juliunus, forced his way to the Dacian capital, won a victory at Tapae (in the east of the Banat), and forced him to sue Domitian for peace. That emperor’s defeat by the Marcomanni prevented him from following up this success, and not merely did he leave Decebalus to all intents and purposes independent, but in the end purchased immunity from Dacian raids by the payment of an annual tribute. Pg2

Before coming to the actual course of the Marcomannic Wars we must mention briefly the fighting in this region previous to the Wars. These conflicts between the Romans and the “barbarians” were not by far so sharp or so dangerous as the Marcomannic Wars, but they did constitute a certain threat to which the Romans had to respond, although -as events were to prove- the measures they took on the Danube frontier were not enough.
A serious disturbance broke out in the central Danube region at the end of the first century A.D., under Domitian, when the Romans undertook a punitive expedition against the Marcommani and the Quadi for not having helped them in the war against Dacia. After they had crossed the Danube the Romans were defeated and had to retreat to within their own frontiers again. Pg.267-268

6- Saturninus rebellion was put down before Domitian even reach there, in 89 both Marcomani and Saturninus problems was resolved, yet Domitian was afraid to cut again the payment of tribute for Dacians, or even to ask for those lost standards. And it was about Pretorian Guard standard, the most important of Roman army, representing the elite unit who guard the emperor himself.

With everything going on with the Marcomanni and Saturninas, Domitian had no choice.
But also see what kind of agreement it was:

This encomiastic statement made by Pliny the Younger makes one infer that Decebalus was also forced to had over hostages in 89. Pg.255

But, given the new historical circumstances, it contained a new element: technical and financial assistance for Decebalus. Still this does not change the character of the treaty - imposed after a dedito- by which the Dacian king has to integrate himself into the Roman political and legal system as one of the numerous reges socii. Pg.190

Unfortunately time is preventing me from further writing and expanding on this.

[Nathan Ross]

Fuscus assembled the V Alaude and the VII Claudia with perhaps the millarian cohorts of the IIII Flavia and I Adiutrix legions. To this force was added a small collection of auxilia.

It should be said that we have no actual evidence of the composition of the force that Fuscus led into Dacia, except that it apparently included units of the praetorian guard. Neither do we know for sure that an entire legion was lost. Tacitus (Agricola 41.2) mentions 'so many armies lost through the rashness of their commanders', which is vague. Dio (68.9.3) mentions a single standard (not an eagle) recovered by Trajan (although I seem to remember the Column shows an eagle...). Suetonius mentions a legion lost to the Sarmatians c.92, but nothing about one lost to the Dacians earlier.

Placing V Alaudae in Moesia, or in Fuscus's army, might seem convenient but is not necessary. It still remains very possible that were destroyed or disbanded after 69/70 (Ritterling and Brian Jones believe so, among others). IIII Flavia were likely still based in Dalmatia until c.86. Fuscus's force most likely involved elements of the legions of the still-united Moesia: VII Claudia, V Macedonica and I Italica, perhaps with vexillations from elsewhere.


Julianus probably thought it prudent to avoid pursuing the campaign in hostile territory in winter and Domitian may have approved or advocated plans for another attack beginning in the following spring

Perhaps. Alternatively, perhaps both expeditions - Fuscus and Julianus - were intended as punitive campaigns, rather than attempts at conquest. Domitian himself accompanied neither force, which he may well have done if he expected the complete subjegation of Dacia. But we will never know for sure...

[Dan Howard]

I say simply because they annihilated the Syrian army and held up fairly well (better than anyone before them, perhaps) to Roman sieges (Jerusalem, Masada). I just wanted to stir the pot, so to speak.

You could certainly make a better case for the Jews being a bigger threat to Rome than the Dacians.

[Titus Manlius Verus]

Disease, Logistical supply, and other factors would make that highly implausible. Same applies to the dacians, who didn't have nearly the capabilities of the Romans.

Are we certain about this? It's evident that the Dacians may have been on the same technology level as the Romans, and most likely outnumbered the Romans. We know that the Romans fought a confederation of Germans, Dacians, and Sarmatians. It's very plausible that 100,000 man battles could have taken place. It seems to me that the Dacians were extremely organized. Also, the Romans most likely brought most of the 100,000 soldiers together for the final battle at the Dacian capital. The Romans liked to march divided and fight concentrated.

I may be wrong, but that's my theory.

[Nathan Ross]

Also, the Romans most likely brought most of the 100,000 soldiers together for the final battle at the Dacian capital.

But where do you get that figure from? One hundred thousand men is a vast army - a force that size would consume 240 tons of food every day, and the produce of 1400 acres of arable land every week. Caesar conquered Gaul with a considerably smaller force, and Plautius invaded Britain with probably half that number. I think you would struggle to find many reliable sources describing a Roman campaign army of that size (battles like Philippi involved a lot of legions, but most of them were severely understrength!).

Besides which, as I've said before, gathering a force of that size would strip the entire Danube frontier of men and leave the border effectively undefended for the course of what could be a very protracted war. That's not even considering how effective such a large number would be in practice: as Alexander the Great allegedly said, a force of greater than forty thousand is not an army but a mob!...

At the risk of repeating myself (!), there is no firm evidence for the total size of Trajan's army, but no contemporary describes it as being the largest, or even one of the largest, ever fielded by Rome. Way back here I roughly estimated a total number of 55,600 men - this is a hypothetical figure (and still very high), but it is to some degree based on inscriptional evidence. To my knowledge none of the very much higher estimates are based on any solid foundation.

[diegis]

Unfortunately i dont have time to answer now point by point to Frostwulf or Nathan.

What i want to point out is that Romans suffered heavy losses and not just that Domitian already bring lots of troops near Dacian frontiers (i think around 8 legions based along Danube from Panonia all along Moesia) but Trajan bring other two and form another two for those wars. This beside the very numerous auxiliar troops and iregular troops raised just for these wars (like German mercenaries showed on the Column half naked and armed just with clubs).

Karl Strobel is one of those who mention numbers as 175,000 Roman soldiers strong army assembled by Trajan in the war zone area

http://www.jstor.org/discover/10.2307/30...1497020967

Both Domitian and later Trajan did take troops from other frontiers and from all over the empire for these wars. The conquest of Caledonia is halted and Agricola and his troops are called back for ex. Legions from Orient, Britania and Germania (alongside Germanic mercenaries, probably bring both as "cannon foder" and to weaken the possibility of troubles in Germania) was bring in by Trajan.

This show the emergency and importance of this confrontation, with the risk of weakening the Parthian and German borders.

And the danger posed by Dacians, if we look at the very few ancient mentions preserved today (beside Tacitus who was already mention and who talk about Roman armies lost to Dacians):

<< Eutropius, Book VII, 23
"Oppius Sabinus, a man of consular rank, and Cornelius Fuscus, the praetorian prefect, were slain with large armies by the Dacians." >>

<< Cassius Dio, Roman History, Book LXVII
"but Domitian sent Fuscus against him with a large force.">>

<< Orosius, Historiae adversum pagano, Book 7
"Domitian, however, who was puffed up by the lowest form of vanity, held a triumph. Nominally this triumph celebrated his victory over the enemy, but in reality it celebrated the loss of his legions.">>

<< Jordanes, Getica
"XIII (76) Now after a long time, in the reign of the Emperor Domitian, the Goths, through fear of his avarice, broke the truce they had long observed under other emperors. They laid waste the bank of the Danube, so long held by the Roman Empire, and slew the soldiers and their generals. Oppius Sabinus was then in command of that province, succeeding Agrippa, while Dorpaneus held command over the Goths. Thereupon the Goths made war and conquered the Romans, cut off the head of Oppius Sabinus, and invaded and boldly plundered many castles and cities belonging to the Emperor. (77) In this plight of his countrymen Domitian hastened with all his might to Illyricum, bringing with him the troops of almost the entire empire. He sent Fuscus before him as his general with picked soldiers. Then joining boats together like a bridge, he made his soldiers cross the river Danube above the army of Dorpaneus. (78) But the Goths were on the alert. They took up arms and presently overwhelmed the Romans in the first encounter. They slew Fuscus, the commander, and plundered the soldiers' camp of its treasure. And because of the great victory they had won in this region, they thereafter called their leaders, by whose good fortune they seemed to have conquered, not mere men, but demigods, that is Ansis.">>

In this last battle Romans lost more then probably at least the battle standard of Pretorian Guard (as Fuscus, its commander, was surely acompanied by the battle standard of his unit), the most humiliating moment for them (and who normally would lead to the disbandement of Pretorian Guard, the Roman army elite who guarded the emperor).
This humiliation is probably the reason why Trajan used them such directly in battle too, to "wash" that previous failure

Then Romans was forced to pay a tribute to Dacians, who kept anyway the captured battle standards and war booty, plus receiving lots of money from the empire, and engineers and military instructors which allow them to profesionalize even more their army, in Roman style, including the construction and use of "artilery" as scorpions, balistae or catapults as its seen on Trajan Column

This made the Roman chronicars back then to "put undercover" and keep silence about those events, as the same Paulus Orosius said:

<< Orosius, Historiae adversum pagano, Book 7
"I would like to tell in detail of the great battles fought by the Dacian king Diurpaneus against the general Fuscus, as well as of the extent of the Roman losses. But Cornelius Tacitus, who wrote an exhaustive history of these events, has declared that Sallustius Crispus and very many other authors established the practice of keeping silence about the numbers of the slain, and that he himself preferred to do likewise.">>

Trajan prepared himself few years for this wars bringing even more troops, reinforcing and rebuilding the fortresses in Moesia, doing engineering work of huge dimenssion on Danube (including the partialy diversion of the river and later building big bridges over). Even so he needed each wars around a year to reach the Dacian capital, Sarmizegetusa, which is located i think at no more then 200 km from Danube, a distance of which Roman legionars can do in a week in just a simpla march.

Trajan of course amassed lots of provisions in the war zone in those years (he had Panonia and Moesia which provided lots of grains for ex, as well Danube allowed ships to travel all over much easier).

Decebalus knew that and the Dacian counter-offensive in the winter of 101-102 AD was specifically done to cut the Roman invasion army, blocked in mountains and by Dacian fortifications, from the logistic bases in Moesia.
If successfull, Trajan and his large number of troops will find isolated in mountains, in winter time (quite harsh here many times) and with logistic bases mostly destroyed.

Thats why he appear on the Column rushing (he is on a horse) with a part of his troops to help those left behind in Moesia to guard the bases. Fortunately for Romans it was a mild winter and the Danube didnt frozed as usual, which allowed them to use boats to move faster along the river

[starman2012]

I'd say the Parthians remained at the top, and overall I think it's a Tie between the Sassanid Persians and the Hunnic Empire.

Goths and Vandals probably did more damage overall. They broke the back of the West.