(I address the Roman Empire and Western Roman Empire, not the Eastern Roman Empire, which employed Vikings.) A Viking is a pirate - from the north and often Norse, but not exclusively so and it is there that the proper answer lies. Britain was a target in Roman and Sub-Roman times. read more
Thus it is impossible for western Romans before 476 AD to ever encounter vikings since no Scandinavians ever went on viking raids to Roman territories until after the western Roman Empire fell. But Roman citizens and subjects and Scandinavians did meet sometimes. For example, Roman artifacts have been unearthed from Scandinavian Roman era sites. read more
Of course the Roman Empire lasted about 2 thousand years, so, yes: they lived at the same time, at one point, but the Wester Empire (the one of Julius Cesar and Octavian Augustus) came and disappeared before the vikings. This doesn’t mean that scandinavians weren’t there: simply they weren’t what we use to call “Vikings”. read more
Romans And Vikings. Rome was an Empire long before the Viking Era. They did not even exist at the same time. However, the successor to the Roman Empire, the Byzantine Empire, centered in Constatinople, did employ Vikings as the Varangian Guard for their Emperor. read more