Pressure on the Frontiers

The fall of the West began not with an attack but with a refugee crisis. Around 375 AD a terrifying new power erupted out of the eastern steppe — the Huns, mounted nomads whose mobility and ferocity shattered the Gothic peoples north of the Black Sea. In 376 a vast throng of Goths, fleeing the Huns, appeared on the north bank of the Danube and begged the Eastern emperor Valens to let them cross into the safety of the empire.

Valens agreed, hoping to gain soldiers and farmers. But the Roman officials charged with settling the refugees instead exploited and starved them, selling them dog-meat at the price of their own children sold into slavery. Driven to desperation, the Goths revolted and began ravaging the Balkans. The Roman response was botched, and in 378 Valens, impatient for glory and refusing to wait for reinforcements, attacked the Gothic host outside Adrianople.

It was a disaster on the scale of Cannae. Gothic cavalry caught the Roman army in the open and annihilated it; two-thirds of the eastern field army and the emperor himself died on the field. Adrianople destroyed the aura of Roman invincibility and, more practically, a generation of trained soldiers the empire could not easily replace. To restore order, Rome was forced to settle the Goths inside the empire as foederati — allied nations under their own leaders, owing military service but never truly assimilated.

This was the fateful precedent. The Western Empire would increasingly depend for its defense on barbarian peoples settled within its borders and barbarian generals commanding its armies — a solution that worked only so long as the bargain held. When the bargain broke, the empire had armed and quartered the very forces that would tear it apart. The emperor Theodosius reunited East and West one last time before his death in 395; thereafter the two halves were permanently separate, and the weaker West was left to face the storm largely alone.