AT: "rc"
William Hartnell was a Human who was kin to descendants of Clare Raymond.
Hartnell's name was read out on a computer display of the Raymond family's genealogy, along with others such as Colin Baker, Tom Baker, Peter Davidson, Jon Pertwee, and Patrick Troughton. (TNG: "The Neutral Zone", okudagram)
William Hartnell is a reference to British actor William Hartnell who played the first incarnation of "The Doctor" in the long-running British science fiction series Doctor Who.