Sister George is a beloved character in the popular radio series Applehurst, a nurse who ministers to the medical needs and personal problems of the local villagers. She is played by June Buckridge, who in real life is a gin-guzzling, cigar-chomping, slightly sadistic masculine woman, the antithesis of the sweet character she plays. She is often called George in real life, and lives with Alice "Childie" McNaught, a younger dimwitted woman she often verbally and sometimes physically abuses. When George discovers that her character is scheduled to be killed, she becomes increasingly impossible to work and live with. Mercy Croft, an executive at the radio station, intercedes in her professional and personal lives, supposedly to help, but she actually has an agenda of her own.
Although it is strongly implied that George and Childie are lesbians, and towards the end it is suggested that Mercy could be as well, this is never explicitly stated. Marcus intended the play to be a farce, not a serious treatment of lesbianism, but because there was so little material about lesbians it became treated as such.
It is usually regarded as a parody of the killing of Grace Archer in The Archers (an episode much better known at the time the play was written than it would be in the 21st century). It may also have been inspired by the sacking of actress Ellis Powell from Mrs Dale's Diary, and has sometimes been compared with What Ever Happened to Baby Jane?. The death of Martha Longhurst (actress Lynne Carrol) in the English television serial Coronation Street in 1964 may also have been an inspiration.
The Killing of Sister George had its premiere at the Bristol Old Vic in April 1965, in a production directed by Val May. After a tour, the production moved to the Duke of York's Theatre in London, opening on 17 June 1965, with the original cast including Beryl Reid as June Buckridge, Eileen Atkins as Childie and Lally Bowers as Mercy Croft. In April 1966 the production moved to the St. Martin's Theatre. On 5 October 1966 the show opened at the Belasco Theatre in New York, with the original cast of Reid, Atkins and Bowers. Hermione Baddeley, Andree Melly and Margaret Courtenay took over at the St. Martin's. Reid won the 1966 Tony Award for Best Performance by a Leading Actress in a Play for the Broadway production.
A West End revival in 1995 starred Miriam Margolyes, Serena Evans and Josephine Tewson. In 2011, a revival at the Arts Theatre in London featured Meera Syal as George. Directed by Iqbal Khan, the cast also included Elizabeth Cadwallader, Belinda Lang and Helen Lederer.
Lukas Heller wrote the screenplay for the 1968 feature film version directed by Robert Aldrich. Beryl Reid was cast as George (although Bette Davis and Angela Lansbury were both offered the role). Susannah York played Childie and Coral Browne took the part of Mercy Croft. In the movie, Applehurst became a television soap opera, and the lesbian aspects of the plot were much more explicit. The film added many characters and shot many scenes on location. The opening sequence has George wandering through the streets and alleyways of Hampstead west of Heath Street. Another is in a real-life London lesbian hangout, the Gateways Club. Childie is portrayed as childishly naive rather than dim-witted, and George is more of an alcoholic. In one scene, while under the influence, George molests two novice nuns in a taxi, behaviour that precipitates the beginning of the end for Sister George.