The fall of the Roman empire was a process, not an event, lasting several centuries. It came from internal political chaos as much as external invasion by barbarians. It was not even that the Romans suddenly stopped being Romans.

The western half of the empire broke apart in the fifth century A.D., when Roman armies were too weak, too poor, and too corrupt to keep the Germanic barbarians off their lands. The Roman army was the backbone of the Roman republic and empire. But it began to fail when the government struggled to collect taxes and the legions relied more and more on barbarian mercenaries. By the end, Roman armies consisted mostly of barbarians who didn’t feel any loyalty to Rome, and often switched sides when it was in their interest to do so.

The Roman empire was overextended when barbarian invasions started to take place in the late third century. In the late 300s, Germanic tribes like the Visigoths were pushed westward by the Huns and crossed the Danube. Then in 410, the Goths, under their leader Alaric, actually sacked Rome. Other groups, such as the Vandals and Attila and his Huns, followed, each invading and ravaging some of the remaining western Roman lands, until finally in 476 A.D., the last Roman emperor of the west was deposed by a Germanic leader named Odoacer. This, though not the only reason, is why the history books say the fall of the Roman empire took place in 476.

But the end didn’t affect the people who lived under Rome in 476, and their children, much more than it had in 400. In many places in the empire, Roman laws and the Latin language were still in use for many generations more, and were only slowly replaced by local languages and local law, which had never been totally suppressed by the Romans anyway.

Many scholars argue over why the Roman empire ended, and whether it was caused by something specific or simply by the sheer weight of too many problems piling up. Some say the cause was too much moral decline; others attribute it to the effects of the climate on the economy; a few even say lead poisoning caused it. Probably all of them were partly right.

But the western half of the Roman empire never recovered. The eastern half survived for another thousand years until 1453 as the Byzantine empire. In the west, the fall of Rome opened the way for the Middle Ages, and the rise of the kingdoms that would eventually become the major European nations we know today.