This topic became relevant to me only recently because I always assumed I'd never be able to find the path back that far. But a 3rd cousin did a bunch of research decades ago, and my aunt sent me a copy of the packet. I nixed the line to Hotspur due to obvious errors, but the research still got me cleanly back to Margery le Despenser... and she opens up to many many many lines of descent from Charlemagne, the Capetian Kings, Scottish Kings, Anglo-Saxon Kings, early Norman/Angevin Kings, Irish Kings, Welsh Kings, and even the Princes of the Kievan Rus. So far, I have not found a Plantagenet, but there has to be one in there somewhere. Basically, once you connect to a Norman, you've got it all, and most people of British descent are probably descended from at least one or two Norman lines. My American gateway ancestor is Charles Rodes of Virginia, a younger grandson of the baronet.