Why did the Roman Empire fall?

First: which Rome fell?

When people ask why Rome fell, they usually mean the western half of the empire, which ended in AD 476. But the Roman Empire had been split for good in 395, when Emperor Theodosius died and his two young sons divided it. The eastern half, ruled from Constantinople, today’s Istanbul, still called itself Roman and lasted almost another thousand years, until 1453.

The long slide in the West

The causes stack up over two centuries:

• Civil war. From 235 to 284 the army made and murdered emperors, more than twenty in fifty years, while Persia and the Goths attacked. In 260 the emperor Valerian was captured alive by the Persians. By 271 the empire had cracked into three.
• A divided empire. Diocletian split power among four rulers in 293, and after 395 East and West went their own ways. The richer East could not, or would not, always save the West.
• Migrations and the Huns. Around 370 the Huns rode out of the steppe and drove the Goths to the Danube. Rome let them in, then mistreated them. In 378 they killed Emperor Valens at Adrianople. In 410 the Goths under Alaric sacked Rome itself.
• Money. In 439 the Vandals took Carthage and North Africa, the West’s breadbasket and its richest taxpayers. Without that money the West could not pay its armies, which were increasingly made up of Germanic soldiers led by generals who made and broke emperors.

The end that nobody noticed

The last emperor in Italy was a teenager whose name sums up the whole story: Romulus Augustus, nicknamed Augustulus, “little Augustus.” In 476 the barbarian soldiers in Italy demanded land. Their officer Odoacer promised it, took Ravenna on September 4 and retired the boy to a villa near Naples with a pension. Odoacer did not make himself emperor. He sent the imperial regalia to Constantinople and ruled Italy as king, keeping the Senate and Roman law.

Thus the Western Empire of the Roman race, which Octavianus Augustus, the first of the Augusti, began to govern in the seven hundred and ninth year from the founding of the city, perished with this Augustulus.

On September 5, 476, almost nothing changed. Romans in Italy still paid taxes, went to court and named consuls each year. Only later writers decided that 476 was the end.

Decline, or transformation?

Historians still argue. Edward Gibbon, in the 1700s, saw “the triumph of barbarism and religion.” Peter Brown sees a creative new world, late antiquity. Bryan Ward-Perkins counts cruder pottery and smaller cattle, and sees living standards collapse. Both can be true. What is certain is how much survived: Portuguese, Spanish, French, Italian and Romanian descend from Latin; Roman law shapes the legal codes of most of Europe and Latin America; and the calendar on your wall is Caesar’s, with the months named for him and Augustus.