William Hartnell

William Hartnell was the first actor to portray the Doctor on Doctor Who. For many, his remains the definitive portrayal of the character, and elements of said portrayal are evident in the performances of all his successors on the television series.

Biography
William Henry Hartnell was born out of wedlock on 8 January, 1908, near St. Pancras Station in London. He was adopted at 16 by Hugh Blaker and got a position performing various backstage jobs with Sir Frank Benson's Shakespearean Company. Moving up into small walk-in parts on the stage, he soon left to pursue an acting career, mostly in comedies. Eventually moving into film, he played memorable roles in The Agitator, Murder in Reverse, Heavens Above, and The Mouse That Roared, co-starring in the last two with Peter Sellers. He was sometimes credited as Billy Hartnell.

Hartnell was selected to portray the Doctor based on his performances in the television series The Army Game and the film This Sporting Life. He played the character of the Doctor from the pilot episode in 1963 to "The Tenth Planet" in 1966. Officially his departure was due to poor health, though some sources cite poor relations with the new production team as another possible factor.

William Hartnell reprised the role of the Doctor in "The Three Doctors" in 1973. Two years later, he died on 24 April at Marden, Kent. For the twentieth anniversary story, "The Five Doctors," archive footage of Hartnell delivering his farewell speech from "The Dalek Invasion of Earth" was used for the opening.