Mary (Madge) Lascelles was the granddaughter of Henry Thynne Lascelles, 4th Earl of Harewood. She never married. She graduated from Lady Margaret Hall at Oxford and became a tutor in English and literature at Somerville College for almost three decades (1931–1960). She also served as a vice-principal. She was elected to the British Academy in 1962. Her insistence on proper English, and her high standards of politeness, punctuality and integrity were well-known and made her as formidable as her scholarship. Among her other works, she was the author of a privately printed Memoir in 1989.