Parthia

Historical References
Horace often conflates the Parthians and the Persians, though he does specify that Parthians are feared for their arrows and quick flight and themselves fear chains/dungeons of the Italians.

Ovid speaks of the Parthians stealing the Roman standards, saying that because they run away in the act of conquering, they will have nowhere to run when they are themselves conquered

Lucan, quoting Pompey, talks about Roman forces fearing the skilled archers and horses of the Parthians as well as their poisoned arrows. Quoting Lentulus’ response, he says that Parthians are strongest in wide-open fields where they can utilize their horses, but that any wall that might stop arrows will then stop the Parthians, especially since they are not especially courageous

It seems to be important that the sarcophagus of Gaius Julius Mygdonius states that he is Parthian by race, albeit also a citizen of Rome