I didn't join Ancestry.com, but I took their DNA test. It's pretty good at locating relatives who have taken the test. When a first cousin on my mother's side took the test, they identified him as a first or second cousin. Similarly, they connected me with a second cousin on my father's side, who sent me a PDF of a book of genealogical info that extended my knowledge of my father's father's family back to a Joseph Smith (c. 1712-1780) in North Carolina.
A friend of mine with an Ancestry.com account located a family tree that one of my father's mother's Mormon relatives had posted there. I don't know how reliable all the connections are (I spotted some that definitely didn't work), but it contains lines that go back to English nobility and from there to many of the royal families of Europe. Name a European king from before the year 1100 who didn't die childless, and he's probably in there. Beyond that, I can use medieval sagas and royal genealogies to trace my line of descent all the way back to Adam, or better yet, Odin!
On the basis of all these dubious sources, I can state with pride that
Sigurðr Fáfnisbana is my great×43 grandfather and Lady Godiva is my great×35 grandmother! And my great×27 grandfather is a
Disney villain!