Whole idea of nation or ethnicity did not even exist few hundred years ago. And Europe was everything but peaceful up until 1945. Don't forget that we had wars

Whole idea of nation or ethnicity did not even exist few hundred years ago. And Europe was everything but peaceful up until 1945. Don't forget that we had wars like "30 years war" where we have essentially depopulated central Europe just because one side had little bit different take on Christianity that the other.