According to researchers on Richard III, having found extraneous DNA in his bones suggesting that Edward III or his son John of Gaunt had some illicit affair and progeny....the thinking that it was Edward, as Gaunt married for love and the marriage was, apparently, a very successful one.
So allowing for the inevitable ascerbic remarks from the AB anti-royalists, "Out you go, Liz Windsor, and you too, Chuck and Bill, to become commoners à la fruity Sue Townshend and "Arise, King John II" - aka Duke of Somerset number 19 and off the legit line.
Interesting eh?
http://www.telegraph.co.uk/news/uknews/theroyalfamily/11268218/Richard-III-DNA-shows-British-Royal-family-may-not-have-royal-bloodline.html