Detroitpete,

Here is a very interesting site for you. If you sign up it is free for 30 days. It does show some of the descendants of Duncan I. maybe you can find ancestors here and then tract back to all kinds of famous personages. You have to look up by first name of title. Wierd but ypu'll get used to it. My ancestor is Col George Reade, so you would look under george first. The page of Duncan I should pop up for you. Good luck. Once you have IDed one person it will calculate the relationship between that person and others you may want to pick out.

http://www.royalist.info/execute/biog?person=534