I'm looking for more information and ancestry to a William Douglas (my 7x great grandfather), supposedly born in Dundee in Scotland around 1640. Hi moved to and setteled in Schippenbeil in Germany where his first (?) son Wilhelm Douglas where born Jun 6 1688. His wife was Maria Niesbeth (?), and he later married to a Dorothee Kienemonth (they got a son named Daniel Douglas). Hi died in Schippenbeil Jan 6 1711.
I'we been told that this William Douglas is a decendant of the Black Douglas, but I can't find the connection. Can you please give me any tips on where to look for clues?