The primary reason for the fall of the Western Roman Empire was a combination of internal weaknesses and external pressures. Internally, political corruption, economic decline, and social unrest eroded the empire's strength. Externally, invasions by barbarian tribes, such as the Visigoths and Vandals, compounded these issues. By the early 5th century, the weakening of Roman authority and military capacities made it increasingly difficult to defend against these threats. The empire's eventual fall in 476 AD, marked by the deposition of the last emperor, Romulus Augustulus, symbolized the end of Roman control in the west and the beginning of the Middle Ages in Europe.