The decline of the Roman Empire in the West was marked by a series of internal and external factors, leading to its eventual fall in 476 AD. Significant contributors included political instability, economic troubles, and military defeats, including barbarian invasions by groups like the Visigoths and the Vandals. The split of the Empire into Eastern and Western halves also weakened the West, particularly as the Eastern Roman Empire (Byzantium) thrived. Social issues, such as declining civic engagement and reliance on mercenary forces, exacerbated the decline, culminating in the deposition of the last Roman emperor, Romulus Augustulus, by the Germanic chieftain Odoacer.