In 376, the west Roman emperor opened the border to.allow the visagoths, who we’re fleeing the Huns, into the empire. Ten years later the visagoths defeated the Roman army and killed the emperor. They were followed by the Huns and a plethora of barbarian tribes. In 476, the western empire was gone.
Similar to the fall of the Carthaginian empire at the hands of the Romans. The Romans were the crude, militarist upstarts. They destroyed all written records of the Carthaginian empire they could find and spurned its maritime empire. A shame. They had a global sea trade 1500 years before recorded (preserved) history.