Why do countries call other countries other names than the countries call themselves??

I have a question:Why do countries around the world call other countries by different names??

Norway : Norge
Germany : Tyskland or Deutschland
Sweden : Sverig
España : Spain
Österreich : Austria
Greece : Hellas
Switzerland :Helvetia
Ireland : Éire
There are many many more...

Surely what ever a country decides to call its self should be the name everyone else calls it! That would be polite :)

(Thanks to the boss for helping to compile this list.. here's her country of origin, just so she doesn't feel left out...Denmark : Danmark)

Wardi presents guestblogger/chief tickler

Thursday, February 09, 2006 posted by Ysblander/Glory/Kudos @ 7:23 PM