Western Rome’s collapse pins the fall on a string of military losses sustained against outside forces. Rome had tangled with Germanic tribes for centuries, but by the 300s “barbarian” groups like the Goths had encroached beyond the Empire’s borders.
Weakening of the Roman legions
At its height, the Roman Empire stretched from the Atlantic Ocean all the way to the Euphrates River in the Middle East, but its grandeur may have also been its downfall.
Economic troubles and overreliance on slave labor
If Rome’s sheer size made it difficult to govern, ineffective and inconsistent leadership only served to magnify the problem.
The arrival of the Huns and the migration of the Barbarian tribes
Unable to recruit enough soldiers from the Roman citizenry, emperors like Diocletian and Constantine began hiring foreign mercenaries to prop up their armies.
when expansion ground to a halt in the second century, Rome’s supply of slaves and other war treasures began to dry up.A further blow came in the fifth century, when the Vandals claimed North Africa and began disrupting the empire’s trade by as pirates.
The Romans grudgingly allowed members of the Visigoth tribe to cross south of the Danube and into the safety of Roman territory, but they treated them with extreme cruelty. So , the Goths rose up in revolt and eventually routed a Roman army and killed the Eastern Emperor Valens during the Battle of Adrianople in A.D. 378.