I'll bet Robert can give us a more complete etymology, but as I recall, "berger" is a common appendage to German names. "Berg" is a mountain (or hill). Anyone living on one (and there are plenty of mountains and hills in Germany) might have been call a "berger", and more specifically by adding the name of the mountain or area. The translation of "Koeningsberger" would be "Kings Mountainer" Or the "berger" found on the end of your subject might be an American spelling corruption of "Bürger" which means "citizen". It is pronounced almost the same as "berger" and might easily have been changed to that spelling here. Matt