Rome.
The barbarians, goths, visigoths, etc all migrated en mass to the richer Rome and, even at that time, there were romans arguing as to why it was a good thing.
The corrupt political class did nothing about this and made the same vapid arguments that the apologists do today.
Illegal immigration weakend Rome and left them without a culture, a soul, and any means of defending themselv es anymore.
They rotted from within as we are today.
...absolutely classic.
Have you ever read any Roman history 333386? (If that is even your real name)
When the Visigoths; Ostrogoths; Goths; Vandals; and Huns "immigrated" into Rome they sacked the city, ploughed up the streets and surrounding fields sowing salt as they went and carried off most of the populace as slaves.
That's hardly "illegal immigration" as you put it, it was a series of invasions...
-410 AD ...Alaric the First (Visigothic king) sacks Rome and empties it's treasury
-455 AD ...Geiseric (Gys Eric) the Vandal king leads a united front of Hun tribes and clans to utterly destroy the already impoverished Eternal City in revenge for the defeat (and subsequent murder) of the great unifying Hun messiah Attila, two years earlier
...There never was any mass immigration of Huns/barbarians into Roman society. Rome was weakened by a confluence of interconnected factors:
-climate change
-corruption
-cultural strife (not from the Huns though)
-mercury/lead poisoning of the equites/senatorial classes and subsequent sterility (long explanation)
-a growing anti-slavery movement (the Huns didn't keep slaves in the same manner)
-power disputes between the elite and plebian factions
-the split of the empire into eastern and western power bases
-continuous outbreaks of malaria (brought back from Africa by campaigning legions)
-friction between enlightened Pagan thought and unenlightened literalist Christianity
During the sack of 455 AD Geiseric found the city in a sorry state, depopulated by vast outlying "Zones of Pestilence" (malaria), the wealthier inhabitants had fled and the city was pale shadow of its former glory.
That's where we get the word "vandalism"... the Vandals destroyed a city that was already in a shambles.
I think you are confusing the terms Rome (the city) and Roman Empire... from the Hun/barbarian perspective there was no "immigration". They expanded their lands as Rome lost control of its far flung border territories, then struck at the heart of their old enemy when the time was right. They weren't under Roman rule when they entered southern France (for example), neither were they paying taxes to Rome... they annexed the land from a decaying empire.
They didn't come looking for work or a welfare cheque.
They were a herding nomadic society, not a settled agrarian society like Rome's. They didn't immigrate with their herds... they seized control of lands no longer patrolled by legions.
A slow cultural subversion of Romanised society did indeed happen something akin to the Mexican subplanting of white America you seem to fear so much... but it was the spread of Hellenized Jews to urbanised areas, not barbarians.
Just out of interest, would you characterize America's invasion of Vietnam as "immigration"?
The Luke