From what I understand, the Roman Empire was the last culture which arose from the general cultural ferment of Antiquity.

Romans still adhered to Ancient Greek and Mediterranian cultural and religious practices, as a kind of inheritors of Egyptian and Greek knowledge.

However as time passed, their cultural knowledge was increasingly incorporated into Barbaric Germanic and Celtic practices and beliefs.

By the 5th century CE, there was little talk about the mythical Hercules, or their old Emperors, and instead local folk heroes, and Christian characters started to gain more prominience.

By the so-called "European Dark Ages" culture and development brought on by Ancient Greece and Rome was largely forgotten, outside of some useful technological findings, and people forged new identities based on old Pagan beliefs, and the new ideas brought on by Christianity. Their epic past forever lost.