Except that "this" is missing the first "n". 
Ok i notice....but is the one with best sound and easy to remember, not all Etymology are alike the realm names, i was reading some on this website.
http://www.etymonline.com/index.php?As far i could understand, the etymology isn't born with the realm, but how others name them, at the beginning there are many variations but sooner or later one remains, specially those easy to pronounce.
In some cases (remember is just my opinion) maybe the people accepted those who are more pretty, ex:
On England, Instead of being called Englanians, or Englanders, they accepted "English"
These were suppose to be my 2 cents, but since i was taxed a 15% of my income only have ยข1.70....sorry..
Peace
