why not looking for certificates?
parents, grandparents,ggparents and so on.....
your fathers or your mothers birth-certificate possible has normally his birthplace, or not?
Karl is the german form of the name with orgin of Scandinavia:
but the variante Carl is also used in english:http://de.wikipedia.org/wiki/Karlhttp://en.wikipedia.org/wiki/Carl_%28name%29