Classical antiquity

The Hellenistic period ended with the rise of the Roman Republic to a super-regional power in the 2nd century BC and the Roman conquest of Greece in 146 BC.

The extent of the Roman Republic and Roman Empire in 218 BC (dark red), 133 BC (light red), 44 BC (orange), 14 AD (yellow), after 14 AD (green), and maximum extension under Trajan 117 (light green)

Ultimately, it was a slow, complex, and graduated change in the socio-economic structure in European history that led to the changeover between Classical antiquity and Medieval society and no specific date can truly exemplify that.