Elsewhere, Kalleh asks, "What are other regional names for people?"

As a kid, collecting stamps, found that a few country's stamps gave a country-name I'd never heard of -- because the name used by the country itself is entirely dissimilar to the name used in our language. The sole example I can recall in that what we call Hungary, the Hungarians call the Magyar Republic.

Is there a name for this phenomenon of divergent names? Also, what other instances are there, and how did they arise?

And did you notice, perchance, that Britain's stamps did not (and do not) show the name of the country?

Richard English