They were not invited as people. They were invited as hands.
After the war, Europe's factories needed workers, its hospitals needed orderlies, its buses needed drivers and its mills needed hands for the looms. The native population was depleted by war and increasingly unwilling to do the hardest, lowest-paid work. So the old colonial channels were simply reversed. The same populations that had served Europe abroad were drawn in to serve it at home.
The mechanism was extraction. The language was invitation. That confusion has shaped everything since.
Look at what was prepared for them. A place for their labour, and nothing else. No housing policy. No plan for their children's schooling. No provision for their faith. No framework for taking part in public life.
Germany was the most honest about it. Its recruits were called Gastarbeiter, guest workers: a person present by invitation whose departure is expected. The Turkish workers who came from 1961 were housed in dormitories and barracks attached to the factories. Not as families. As labour units.
In Britain, the earliest arrivals found everything that was not the job for themselves. The housing. The mosque. My grandfather did exactly that, because help was never part of the arrangement.
Then follow the consequences, because they were entirely predictable.
The workers took the jobs nobody else wanted: night shifts, assembly lines, cleaning, heavy lifting. They were paid less, and often shut out of the unions that might have improved things. They lived where they could afford to live, which was where no one else wanted to live: the oldest terraces of the industrial towns, the shanty towns outside Paris and then the tower blocks the French working class was leaving, the cheapest rentals of the Ruhr.
They did not choose to live together at the edges. The edges were what their wages bought.
Decades later, the same societies would look at those neighbourhoods and see a problem of the residents' own making. Ghettos. Parallel societies. Failed integration. Policy papers would diagnose it. Politicians would decry it.
None of them would say the obvious thing. You cannot import people as a factor of production, provide for nothing but their work, and then blame them for the shape of the lives they built in the gaps.
The workers stayed. They brought their families. They had children. They built communities in soil nobody had prepared for them. That is not a failure of integration. It is an achievement, made without help, against a design that never expected them to settle.
Now the invitation is being rewritten as an intrusion, by the civilisation that sent it.
Europe did not build a place for the people it invited. The people built one anyway. The question is whether Europe will admit which of those two things is the scandal.