What Kind of Cultures Were in Place in the Middle Ages?

In aboriginal australia people were able to travel half way across the continent, moving across people who spoke entirely different languages. And yet still you will find camps that had people of yon their sam totemic moity and treated them like brothers and sisters. We could only really guess as to what kind of systems were like, and how those systems might have worked forty thousand years ago. If not for the enforcement of language satenization through the school system, we would actually see an even more rapid explosion of linguistic diversity developing out of cruels. You know, at a couple of centuries from now trinaan dialects may be entirely incompatible with british or anglo-ac