I have been wondering where names for countries in English come from. Why is it that we call Germany Germany, when it is called in German Deutshland? Japan when it is called in Japanese Nihon? Croatia when it is called in Croatian Hervatski? There are heaps of others, but my point is, why doesn't everyone call every country the same thing, which people native to that country do? Where do the other names even come from?

http://en.wikipedia.org/wiki/Names_for_Germany

if you read the wohle page you get a good impression how it works for almost every language and country ..