The Roman Empire's Greatest Enemy

Who was the greatest foe of the Roman Empire?

It was the Sasanians.

I have readen recently that the roman emperors considered Persia as the real threat. We can also say that the persian were never defeated by the Romans like the Huns were in 451.
We can also remember this:
https://en.wikipedia.org/wiki/Battle_of_Carrhae
It was not under Shapur I, but it demonstrates us that the persians were able to achieve complete successes against the Romans.

I woul disagree. Sasanians was worthy opponent to the romans, but it dont they dont apear to pose ann existential threat to the Roman empire the way huns did. Roman-sasanian wars was fought at the perifery between two empires and sasanians never invaded roman core territories and probably could not do so.

ceaserkhan22 wrote:Who was the greatest foe of the Roman Empire?

The greatest enemy of a Roman, was another Roman.

The Last Savoyard wrote:It was not under Shapur I, but it demonstrates us that the persians were able to achieve complete successes against the Romans.

No, it demonstrates a pretty common theme in Roman military history: A Roman army was only as good as the general at the head of it. Crassus was a businessman, not a general.

Sasanians. The Germanic tribes and Goths brought about the fall of Rome but the Sasanians were opposing Rome for centuries.

If Rome was Superman, then the Germanic tribes are Doomsday. The Sasanians were Lex Luthor.

I would say either Khousu of the Sassanids for nearly destroying the empire in the early 600's or the Muslim states that eventually wiped it out.

I've said this before, But the greatest enemy of the roman empire was the Parthian empire.

People really underestimate the crucial effect that Trajan's parthian campaign had on the roman empire. Trajan failed to attain the vast and rich resources of the east, Which stopped roman expansion far more than teutoburg forest ever did.

The empire would still linger on for 1336 years, But the age of an expanding roman state was gone.

I don't consider Arminius to be a major threath, He defeated Varus at Teutoburg and forcer Rome out of Germania, but never posed a threath as the Huns, Visigoths, Southern Germans or Sasanians did

I am going to go with Huns
Also I dont believe Battle of Chalons was a defeat for Attila he just wanted to clean his way before the real invasion(452).
It was more of Roman propaganda art that Flavious Aetius won the war
Thats just my opinion though.
Only sources we have about the war belongs to Romans after all