I'm a direct descendant of an illegitimate child of Edward Longshanks and a Scottish mistress.
So how far back in history can you trace your ancestry?
Well, depends on who you ask. My family on my mother's side is Mormon, so they have it "all the way back to Noah". It seems to be legitimately traced back to a few hundred years before Edward, so maybe 800 or 900 AD. At some point all Mormons take widely accepted (to them) shortcuts that get them back to Adam. It's kinda nutty, but I do appreciate all the real work they have put into the genealogy up to that point.