Gladys Maude Winifred Mitchell - or 'The Great Gladys' as Philip Larkin called her - was born in 1901, in Cowley in Oxfordshire. She graduated in history from University College London and in 1921 began her long career as a teacher. Her hobbies included architecture and writing poetry. She studied the works of Sigmund Freud and her interest in witchcraft was encouraged by her friend, the detective novelist Helen Simpson.

Her first novel, Speedy Death, was published in 1929 and introduced readers to Beatrice Adela Lestrange Bradley, the detective heroine of a further sixty six crime novels. She wrote at least one novel a year throughout her career and was an early member of the Detection Club, alongside Agatha Christie, G.K Chesterton and Dorothy Sayers. In 1961 she retired from teaching and, from her home in Dorset, continued to write, receiving the Crime Writers' Association Silver Dagger in 1976. Gladys Mitchell died in 1983.