Final answer:
The fall of the Roman Empire was due to a mix of internal issues like political chaos and external pressures from aggressive neighbors and barbarian invasions, with no single primary cause.
Step-by-step explanation:
The fall of the Roman Empire is a complex historical event with multiple contributing factors, both internal and external. Key internal problems included political chaos, such as the Praetorian Guard auctioning off the throne, assassinations, and the retreat of Roman elites to their estates, leading to economic disparities. Externally, Rome faced aggressive new enemies like the Sassanids, and the better-organized and more populous barbarian groups on its northern borders that eventually overcame Rome's military defenses. Additionally, the loss of territories, the shift of capital to Constantinople, and the societal strains caused by continuous conflict all contributed to Rome's decline and eventual fall.
Despite these challenges, it is remarkable that Rome, as an entity, persisted for centuries before the western half fell in 476 CE. The eastern half, known later as the Byzantine Empire, continued until 1453. The fall of Rome is not attributed to a singular cause but is rather seen as a result of a combination of factors that overwhelmed the once mighty empire. Therefore, it is oversimplified to declare a primary cause for the fall of Rome, as it was a culmination of many complex issues.