Turning a Surname French

Well, I couldn't find anything on French specifically, but this site does seem to have some clues as to its origin that may be helpful.
http://www.bluefat.com/Carmilla/Karnstein.html

If that link is correct, then thinking of the name as meaning "ally rock" might be a good idea, even though it might have been named "rock rock" by mistake from two different languages. "Ally-rock" in French would be "allie-roche". As a family name, either "Alliroche" or "Rocheallie" would work.

There are several possible way to frenchify this name.

You could imagine the name passed into French early in the middle ages and was then adapted to French phonology, and underwent modifications according to French evolution.

So something like "Charstan", with the "s" silent.

You could also have the French name derived from a latinized version of the German name, so Karnstein > Carnisteno > Chernétein.

This has the advantage of avoiding the etymology problem; I am not sure but I also think name are less likely to be translated and more likely to be directly adapted to the target language, like how Old German "Chlodovech" became, as it was adapted several time, "Clovis", "Ludovic" and finally "Louis".

Another possibility is that it would be Frenchified the way that "Sarkozy" or "Strauss" have been. Then there are all those French in Lorraine with German names.

King Neptune said:

Another possibility is that it would be Frenchified the way that "Sarkozy" or "Strauss" have been.

Click to expand...

"Sarkozy" is Hungarian, I believe, and "Strauss" is clearly German. Neither hve been "Frenchified", any more than my mother's surname Christiansen, from her birth in Denmark, has been "Englishified." You can't anymore assume a person's nationality from their names:

Race driver Dario Franchitti (Scotland)
Race driver Emerson Fittipaldi (Brazil)
Basketball star Manu Ginobili (Argentina)
Famous biostratigraphic geologist Wolfgang Volkheimer (Argentina)
Famous biostratigraphic geologist Hideo Haga (American)
Football star Ndomakong Suh (American)
President of the United States Barack Obama (American)

caw