Doctor Who: The Strange Legacy of The First Doctor and William Hartnell
Aside from all these Hartnell suffered from arteriosclerosis, a hardening of the arteries that caused him memory problems. It wasn't too difficult during his run, and he returned to demanding work on stage immediately after ceding the role to Patrick Troughton, but by the time "The Three Doctors" in season ten he could only appear in pre-filmed segments reading cue cards. He died two years later at the age of 67.
The First Doctor wasn't done, though. He would return along with his four subsequent incarnations to celebrate the show's 20th anniversary in 1983's "The Five Doctors." Hartnell was obviously unavailable, but Ian Levine, an unofficial fan consultant, suggested stage actor Richard Hurndall as a replacement rather than using pre-used footage. Ironically, pre-used footage was all of The Fourth Doctor we saw as Tom Baker refused to appear in the series again so soon after his own departure two years prior.
Hurndall ended up bringing his own take on the character, but was also very faithful to the crafty, if acerbic tone of Hartnell. Hurndall was never able to return to the role, though. Like Hartnell, Hurndall's performance in a multi-Doctor special was the last performance of his life, and he died months later without ever cashing the check he earned.
Here's another strange bit of Whoniverse trivia. William Hartnell not only played The Doctor, he actually exists within the same world as him. In January of 2006 Colin Baker took the Sixth Doctor on a romp through 1936 Brighton as part of a Big Finish audio story called "Pier Pressure." The Big Finish productions have been something of redemption for Baker's Doctor, who usually ranks at the bottom of the list of favorites.
The story features Billy, an actor who stars in two films, While Parents Sleep and I'm an Explosive. Both of these are films in which Hartnell, who was often credited as Billy when younger, appeared in in real life. While Hartnell was off filming Doctor Who in the '60s, The Doctor himself was also hurling uncontrolled through time and space in a ship he could barely fly.
Fifty years after Hartnell let Lambert take him to lunch to pitch a kid's show about time travel to him, he is still remembered with great fondness, and somehow he still manages to contribute to the eternal mythology of Doctor Who. And like the character he brought to life, he thoughtfully left behind enough mystery so that there would always be more to explore. I have no doubt David Bradley will do both Hartnell and the Doctor proud justice, and The First Doctor's prophecy from "The Dalek Invasion of Earth" will come true once again.
"One day, I shall come back. Yes, I shall come back. Until then, there must be no regrets, no tears, no anxieties. Just go forward in all your beliefs and prove to me that I am not mistaken in mine."