Why did the Western Roman Empire fall?

The fall of the Western Roman Empire was a multifaceted process driven by a combination of external pressures and internal instability.1

External Factors

The empire faced persistent challenges from "barbarian invasions," particularly during the 5th century CE. Migratory Germanic peoples, such as the Visigoths, Vandals, and Franks, as well as the Huns, placed immense strain on the frontiers. Following the Roman defeat at the Battle of Adrianople, the empire increasingly relied on foederati—tribal allies settled within Roman borders—to bolster its military, leading to the "Germanization" of the army.12

Internal Instability

Internal governance suffered from systemic issues, including:
* Corruption and Abuse: A pervasive culture of extortion and the selling of government posts undermined administrative integrity.13
* Economic Difficulties: Heavy taxation and the consolidation of landownership left the poor vulnerable, while the Western provinces grew weaker compared to the wealthier East.43
* Political Turbulence: Following the death of Theodosius I in 395 CE, the empire remained permanently divided, leaving the West isolated.42

The decline culminated in 476 CE when the German chieftain Odoacer deposed the last Western emperor, Romulus Augustulus.14