This is something I have written about before, so you may find this answer to be of interest. The short of it is that you, me, and everyone else of European ancestry is descended from Charlemagne. Happy to do my best with follow ups you may have.
Starting from Charlemagne and moving forward in time, it's easy to track the lineage to about George Wyatt (1553–1624) and confirm that all of the descendants listed actually form a line.
After that point, the line loses it's title, so easily available and verifiable records become less accessible.
Once you're starting at the top of your list and moving down (backwards in time), you're getting in to genealogist territory and out of historian.
I would suggest heading over to r/genealogy and reading the side bar for tips on starting your family tree search if you want to confirm the info & connect back to George.