Born in London on 4 May 1910, daughter of Charles F. G. Masterman, politician and author, and Lucy Blanche Lyttelton, author and poet. She was educated at Hamilton House, Tunbridge Wells, the Institut Brittanique in Paris, and Newnham College, Cambridge (1929-1932) where she read Modern and Medieval Languages and Moral Sciences.
In 1932 she married Richard Bevan Braithwaite, Fellow of King's College, Cambridge and later Knightsbridge Professor of Moral Philosophy at Cambridge University. They had a son (b 1937) and a daughter (b 1940).
During the 1930s she turned her attention to drama and founded the High House Barn Theatre in Shere, Surrey in 1932 and continued to support it until 1939. She was also active in the Westminster Theatre (1934) and worked as House Manager and Director to Community Theatres (1935-1936) in Brighton. It was during this time that she published three novels: 'Gentleman's Daughters' (1931), 'The Grandmother' (1934), 'Death of a Friend' (1938), and wrote three plays: 'Tennis Party', 'A Question of Method', 'Through the Looking-Glass'.
In 1939-1940 she played a leading part in the formation of the Cambridge Refugee Committee.
In 1959 she became a lecturer in a Cambridge University course in the Moral Sciences Faculty on Philosophy, Language and Languages. She was also Director of Studies in Moral Sciences for Fitzwilliam House (as it then was) and St. Catharine's College.
In the late 1950s the Cambridge Language Research Unit was established based on an idea of Margaret Braithwaite's that the development of computers would soon make automatic translation a feasible goal. Margaret became first the Principal Investigator and later Director of the Unit. Hopes of subsequent research into the nature of language itself were not realised and the Unit ceased to exist following Margaret's death.
Margaret Braithwaite was one of three Newnham graduates (the others being Anna Bidder and Kathleen Wood-Legh) who instituted the Dining Group in 1950. The Dining Group became formally known as The Society of Women Members of the Regent House who are not Fellows of Colleges, and its purpose was to have concern for the needs of women with home responsibilities trying to maintain or resume their academic responsibilities. The group was formally recognised by the University of Cambridge, as an Approved Society for women graduates in 1965. Margaret Braithwaite was a Founding Fellow of the Lucy Cavendish Collegiate Society and its first Vice-President (1965-1975). She was elected as Emeritus Fellow in 1980. She was also a great-niece of Lucy Caroline Cavendish, after whom the College was named.
In 1950 Margaret Braithwaite helped found the 'epiphany philosophers': scientists and philosophers concerned with the connections of their subjects with religion, and became involved in the publication of the journal Theoria to Theory, first published in 1966.
She died in Cambridge on 1 April 1986.
This collection comprises minutes of the Dining Group and its successor, the Lucy Cavendish Collegiate Society; miscellaneous correspondence and memoranda relating to significant events in the College's early history; press cuttings and articles on women's education and work generally.
The papers are a miscellany found in a box amongst College Office papers in March 1995.
The papers are arranged into a simple chronological sequence, 1962-1972.