I'm sorry, i disagree rather strongly that Rome was conquered by it's "slaves".
The internal problems of a social, economic and political nature plagued the Roman World since the late Roman Republic and these problems brought about a decline that ultimately led to the collapse of the Western Roman Empire. However, the invasions of the Germanic tribes, particularly those of the fifth century, were just as important in setting off the internal crises of the western empire and in significantly changing the political map of the west. .
Germanic peoples were known to the Romans since the second century B.C.E. and despite many differences, the two groups did co-exist relatively peacefully. Many Germans had been allowed to cross the border, and they settled as farmers and slaves. Some even became soldiers in the imperial army. The Germans admired what was worthy in Roman civilization and the Romans admired the physical strength and the simplicity of values of the Germans.
They were not slaves!!