Interested in gauging how 'common' (for lack of a better word) the current situation in Europe is. Ignoring settling the New World and uninhabited lands, has the world seen a major migration such as the current one to an already populated area?
Yes, and in fact the migration period is an important part of history. I'm not quite sure what you mean by 'the current situation' though, so I can't really go into much detail. Is it the religious aspect you are getting at, the distance traveled, something else?