There is something to be said of for the individual cultures being even stronger during those times. Perhaps the formation of the German nation state was a counter reaction to the Napoleonic wars?
Anyway, this has little to do with immigration from all over the world: All these kingdoms already had the same language and largely the same culture.
Have states such as France ethnically cleansed other peoples from within their borders? If so, then why isn't that mentioned in the well-known histories?
[https://en.m.wikipedia.org/wiki/Joan_of_Arc] [https://en.m.wikipedia.org/wiki/French_Inquisition]
It did somewhat calm down once the Republic’s formed, but even today there are large conflicts with ‘Normal’ French society and the large scale ghettos from (typically Muslim) immigrants and refugees in France.
The nation state of Turkey's establishment out of the ethnically diverse Ottoman Empire deployed all of the above.
> Other instruments are suppression of ethnic identity, deportation and encouragement of emigration.
If there are good sources to read about this occurring I would love to read them. Otherwise the insinuations are baseless.
That goes back to at least 1095. Or the Inquisiton? [https://en.m.wikipedia.org/wiki/Inquisition]
Notably, it was exceptionally common for Religion to overlap almost exactly with Ethnicity (for various reasons), so the fighting between different Sects was often a common proxy for fights between different Ethnic groups too.
Also, since different Ethnic groups tended to ‘own’ different countries, each time there was an invasion, one would either make ground, or get repelled ‘back where you came from’, which also tended to align ethnic groups by borders. Those efforts didn’t generally merit note. If ‘your side’ lost, even if you’d lived there for a couple of generations, of course you’d lose your land and need to flee ‘home’.
Paris is one somewhat notable exception though.
Language is also an interesting proxy for this. Spanish vs French vs German vs English, etc.
still, there was always the ‘European’ Spaniards, vs the Moorish Spaniards, eh? Splits within splits.
It was always a mix of different peoples - Celtic, then Romans when they invaded, then various Germanic peoples (including the Franks that gave the country it's name)... even the standardization of the French language is fairly modern. We had Occitan and Provincal and Breton spoken, it's only in the past ~200 years or so that industrialization has given a "uniform" culture.