When “Doctor Who” first began back in 1963, the BBC tapped veteran British actor William Hartnell to play the First Doctor. Though he was only 55 when he got the role, Hartnell portrayed an abrasive, seemingly frail, much older Doctor. Being a Time Lord, of course, meant that he was far tougher than he looked, but the frailness wasn’t always an act. Hartnell suffered from then-undiagnosed arteriosclerosis, and as the years went on, the demands of the show took their toll on his health.
In 1983, Doctor Who Magazine #83 contained an interview with Hartnell’s widow, Heather Hartnell, about his time on the show. He absolutely loved it, she assured fans, and left “purely because of his ill health.” In fact, leaving broke his heart. “Having told the press that it was going to run for five years, he was determined to play it for five years. But he could not remember his lines, plus his legs were beginning to give way at times.”
Of course there were rumors that he also left in 1966 because he clashed with the show’s new team, though officially the BBC only says that, “A combination of ill-health and changing production team influenced William Hartnell’s decision to retire from the role.” Not wanting to cancel their hit, the BBC hired actor Patrick Troughton to take over as the Second Doctor, beginning the painful Time Lord regeneration that’s allowed “Doctor Who” to continue for almost 60 years.