She is best remembered for her screen performances as the older mistress of the central male characters in both Saturday Night and Sunday Morning (1960) and This Sporting Life (1963).

After a Baptist upbringing (against which she rebelled), followed by study at the University of Wales and the Royal Academy of Dramatic Art, she began working with a repertory company in Swansea in 1950.

Her portrayal of Brenda in Karel Reisz's Saturday Night and Sunday Morning (1960) won her a British Academy Film Award.

[3] Lindsay Anderson cast her as the suffering Mrs Hammond in This Sporting Life (1963), earning her another BAFTA and an Oscar nomination.

In theatre, she performed at the Royal Court and played the title role as the life-enhancing prostitute in Lionel Bart's musical Maggie May (1964).

(1973), although the haunting Australian-made Picnic at Hanging Rock (1975), directed by Peter Weir, provided her with a different kind of role, as the authoritarian head teacher of a Victorian girls' school.

[9] She had a habit of imitating a Welsh Corgi when intoxicated and once, at a party thrown by Richard Harris, attacked actor Robert Mitchum on all fours, chewing his trousers and chomping on his bare skin, while he patted her on the head, saying "there, there".

[10] In diary entries from June 1967, Richard Burton describes a visit from the Harrisons where "Rachel became stupendously drunk and was or became totally uncontrollable...She insulted Rex sexually, morally, physically and in every way.

[14] An autopsy later determined that her death was a result of swallowing lye or another alkali, or another unidentified caustic substance, as well as barbiturates and alcohol, as detailed in her posthumously published journals.