Born Jan 8,1908 in London, England. Died April 23, 1975 in Kent, England.
Hartnell acted in a number of English plays where he was usually cast as a tough guy: thug, policeman, soldier, etc. Verity Lambert, the producer of Dr Who. offered him the title role in 1963 after seeing him in a London play called "This Sporting Life." Hartnell took the part with some misgivings but eventually came to like it because he was a hero to the kids who watched it instead of the threatening parts he had played earlier.
Hartnell had some long standing health problems which worsened in 1966. He also had some difficulties with the production staff after Verity Lambert left, so he decided to leave the show. Some one (unknown) came up with the idea of Regeneration to keep the show going after their lead character was gone, and Patrick Troughton was selected for the second Doctor.