The first hint is the word "Visigoth"
The second hint is something to do with Rome
The solution is the sacking of Rome by the Visigoths (a western group of Goths) who were led by Alaric I.
For further information see the documentary The Dark Ages: The Sacking of Rome. I started watching it and learned about this historic event.
Maybe it is time to watch Rome - the complete series. The younger generation keeps telling me how awesome it is.