That’s a bit of an insult to the fifth century, which had its highlights—most significantly the retreat of the Roman Empire, especially from Britain. (Opinions of the Hunnic Empire vary, of course.)
The ways of the “religion” in question don’t belong in any century, even the antediluvian ones.
The departure of the Romans from England was a highlight? That was a tragedy. They fell back into chaos, and stopped building roads until the Norman conquest.
The Romans were the best thing to ever happen to those isles.