One of my father's cousins was able to trace one side of our family tree back to Cunedda. (b 386)
http://en.wikipedia.org/wiki/Cunedda In resonse to the earlier question about why do people always seem to be related to someone famous, I have to answer that most people if you go out far enough can claim someone as a 12th cousin 4 times removed and that is more exciting than saying a have a great grandfather called Edward who was a ship's captain. Plus we often know more about famous people so once you can trace to them their lineage may be known and that fills in gaps.