Margery Louise Allingham was born on May 20, 1904, the daughter of Herbert John Allingham, an editor and journalist, and Emily Jane Hughes, her father’s first cousin, who also became a journalist. By the time of her birth, the family lived in Essex, where every weekend they entertained a number of other journalists. Although the young Allingham had two siblings, she spent many of her childhood hours alone, often writing. At seven, Allingham published a story in the Christian Globe, a publication of which her grandfather was editor. That year she went away to the first of two boarding schools; she left the second, the Perse School for Girls in Cambridge, when she was fifteen.
Finally, Allingham enrolled in the Regent Street Polytechnic in London as a drama student, but her first novel, Blackkerchief Dick: A Tale of Mersea Island (1923), an adventure story set in Essex, had already been accepted for publication, and when her friend Philip “Pip” Youngman Carter convinced her that her talents were more suited to writing than to acting, she left school to work on another novel. In 1927 she married Youngman Carter, who had become a successful commercial artist.
With the publication of her first mystery novel, The White Cottage Mystery, in 1928, Allingham settled into her career. In The Crime at Black Dudley (1929), she introduced Albert Campion, the amateur detective who was to appear in all the mystery novels that followed.
In 1929, Allingham and her husband moved to Essex; in 1934, they purchased their own home, D’Arcy House, expecting to live and work quietly in the little village of Tolleshunt D’Arcy. World War II soon broke out, however, and with Essex an obvious invasion target, Allingham became active in civil defense, while her husband joined the army. Her autobiographical book The Oaken Heart (1941) describes the fear and the resolution of Britons such as herself during the first months of the war. In 1944, Allingham returned to her mysteries. She and her husband made periodic visits to their flat in London but lived in D’Arcy House for the rest of their lives. Between 1929, when she wrote the first Campion mystery, and her early death of cancer on June 30, 1966, Allingham worked steadily, averaging almost a volume a year, primarily novels but also novellas and collections of short stories. Before her husband’s death in 1970, he completed Cargo of Eagles (1968) and wrote two additional Campion novels.