the Roman empire was utterly destroyed and in the process suffered from the genocidal murder of its citizens. The barbarians were quite angry at the Romans for having a better organized society. They slaughtered the Romans like dogs when the Romans became too degenerate to defend themselves. Sort of like America today.
They never should have let brown people in. It's a story that repeats itself eternally...like the Big Bang, contraction...singularity... all that shit.