 Complete the following phrase:  The Western Roman Empire began to disintegrate in the early 5th century as Germanic migrations and invasions overwhelmed the capacity of the empire to assimilate the migrants and fight off the invaders. The Romans were successful in fighting off all invaders, most famously Attila, though the empire had assimilated so many Germanic peoples of dubious loyalty to Rome that the empire started to dismember itself. Most chronologies place the end of the Western Roman Empire in 476, when Romulus Augustulus was forced to abdicate to the Germanic warlord Odoacer. By placing himself under the rule of the Eastern Emperor, rather than naming a puppet emperor of his own, Odoacer ended the Western Empire. He did this by sending the imperial regalia to the Eastern Emperor Zeno, in effect declaring Zeno sole emperor, and placing himself as his nominal subordinate. In reality, Italy was now ruled by Odoacer alone. The Eastern Roman Empire, also called the Byzantine Empire by later historians, continued to exist until the reign of Constantine XI Palaiologos. The last Roman Emperor, he died in battle on 29 May 1453 against Mehmed II the Conqueror and his Ottoman forces in the final stages of the 