Due to how long ago the Plantagenets are now, and how well-connected/well-married they were (and they were big families), I'd be surprised if most people with ancestry in the B.I. are not descended from them in some fashion.
I hadn't expected to be, at all, and holy crap, a couple of generations of tough political times here and there, and whammo, back to the hoi polloi with ya. Not so much as a passed-down story, leave alone any spendables.
I'm descended from Alfred the Great, William the C., various other crowned heads of England and whatnot, including Charlemagne (via his grandson, Charles the Not-so-good /jk), and of course mostly from people now found in history books, because, also surprisingly, most of the time their graves are long since lost or even destroyed, even those of kings.
Somewhere along the line, we’re all probably cousins, and just don’t know it. I recently found out that a neighbor who has lived in this building about as long as I have (20 years), is related to my 9th Great-Grandfather George Soule, who came over on the Mayflower, and was a signer of the Mayflower Compact. It’s a very small world.