Glad to find this group!

[Spider Jerusalem]

12. I've found a few instances of things like that tracing my own ancestry

there's a lot of mistaken identification based on "the name's the same, so they must be related". One of my immigrant ancestors was a Samuel Handy who came to Maryland from England in 1665; he married a woman named Jane Sewell in 1679. Someone who did the Handy genealogy in the 19th century identified her with Jane Sewall, daughter of a Henry Sewall (who was secretary of the colony under the second Lord Baltimore) and his wife Jane Lowe, who was descended from Edward III of England. The only problem with this is that Jane Sewall was married to someonee named George Brent, and having children by him, at the same time as Samuel Handy and his wife Jane were having children, so it obviously wasn't the same woman.

Even so, the odds are that anyone of European ancestry is descended from European royalty; very probably anyone with any English ancestry at all is a descendant of William I, and anyone with European ancestry is almost certainly a descendant of Charlemagne. Whether one can trace back to it it something else, though, since in most cases the records just won't be there. I can trace a lot of my ancestry back as far as the original immigrant to America, and in most cases know where they emigrated from; in some cases, a few generations back on the other side of the Atlantic; and there are one or two lines that go back to medival nobility and royalty, but those are very much the exception.