That can be a tricky question. OronD's answer is the most popular answer, but it depends on one's point of view. As Richie18 pointed out, the Eastern Roman Empire (known to history as the Byzantine Empire) continued to exist for about another millenium after the Germanic king Odaocer seized power in Rome in 476 AD. Where it gets complicated though, is that Odaocer chose not to declare himself Emperor...he instead sent word to the Eastern Emperor in Constantinople of his intentions to set up his own kingdom in Italy, but recognized the authority of the Eastern Emperor (Zeno) as the legitimate Roman Emperor (and actually, the Western Emperor Romulus Augustus that Odaocer had deposed in Rome was a usurper to the throne anyways...the true western emperor Julius Nespos was in exile). Another point to consider was that the Pope was arguably already more powerful than the Emperor at that point. It was the Pope who ultimately negotiated Attila the Hun's to retreat for instance. The Western Empire was falling apart, but the Pope maintained religious authority throughout Europe even after the "fall of Rome". In many ways, the Pope was the heir to the West. During the middle ages when Charlegmagne rose to power, it was the Pope who crowned him "Emperor of the Romans". The Pope also crowned the subsequent Holy Roman Emperors. History views the Holy Roman Empire as a separate Germanic empire, and in many ways that is accurate portrayal, but at the time, the Emperors during that period viewed themselves as the heirs to the original Roman empire. So the length of how long Rome lasted depends on your perspective of when it ended...if it ended at all. In some peoples eyes, since the city still stands and has existed continually with the same religious authority, it never really ended.