He was born in St Pancras, London. Often known as Billy, he was educated at home and at Imperial Service College. After training as a jockey, and boxing, he entered the theatre in 1924. The first of more than sixty film appearances was Say It With Music in 1932. Hartnell usually played comic characters, until 1944 with the robust role of sergeant Ned Fletcher in The Way Ahead. From then on, he played mainly policemen, soldiers, and thugs, like Dallow in Brighton Rock. In 1958 he appeared in the first Carry On film, Carry On Sergeant as Sergeant Grimshaw.
He appeared first on television in The Army Game from 1957-1961, and in 1963 gave up movies and took the lead in Doctor Who, for which he is now most widely known. (See List of Doctor Who serials.)
He was a tough person to work with, according to the documentation about him. His poor health - arteriosclerosis and cerebrovascular disease brought on by years of alcoholism - as well as poor relations with the new production team forced him to leave Doctor Who in 1966, although he reprised the role in the 10th Anniversary story The Three Doctors (1973) with the help of cue cards and pre-recorded inserts. A clip of his scene from the end of the serial The Dalek Invasion of Earth (1964) was used as a pre-credits sequence for the 20th anniversary story The Five Doctors (1983).
Hartnell was born in St Pancras, London, England, the only child of an unmarried mother, and raised primarily by his aunt Bessie (Wood, 208).
Hartnell never discovered the identity of his father (whose particulars are left blank on the birth certificate) and, despite efforts made by Hartnell in later years, was never able to trace him.
Hartnell came to relish particularly the attention and affection playing the character brought him from children, and he became very fond of the role which also earned him a regular salary of £315 per episode by 1966.
Hartnell designed the dresses worn by Queen Elizabeth II on her marriage to Prince Philip, Duke of Edinburgh in 1947, and her coronation in 1953.
On the death of Queen Elizabeth's mother, the Countess of Strathmore, Hartnell remade the Queen's entire wardrobe in white, resurrecting the ancient French usage of white as royal mourning.
Hartnell never married, and instead moved in theatrical circles, counting famed photographer Cecil Beaton and socialite Bunny Roger as close friends.