"Adultery is a meanness and a stealing, a taking away from someone what should be theirs, a great selfishness, and surrounded and guarded by lies lest it should be found out. And out of meanness and selfishness and lying flow love and joy and peace beyond anything that can be imagined."
Macaulay began writing her first novel, Abbots Verney (published 1906), after leaving Somerville and while living with her parents at Ty Isaf, near Aberystwyth, in Wales. Later novels include The Lee Shore (1912), Potterism (1920), Dangerous Ages (1921), Told by an Idiot (1923), And No Man's Wit (1940), The World My Wilderness (1950), and The Towers of Trebizond (1956). Her non-fiction work includes They Went to Portugal, Catchwords and Claptrap, a biography of Milton, and Pleasure of Ruins. Macaulay's fiction was influenced by Virginia Woolf and Anatole France.
During World War I Macaulay worked in the British Propaganda Department, after some time as a nurse and later as a civil servant in the War Office. She pursued a romantic affair with Gerald O'Donovan, a Writer and former Jesuit priest, whom she met in 1918; the relationship lasted until his death, in 1942. During the interwar period she was a sponsor of the pacifist Peace Pledge Union; however she resigned from the PPU and later recanted her pacifism in 1940. Her London flat was utterly destroyed in the Blitz, and she had to rebuild her life and library from scratch, as documented in the semi-autobiographical short story, Miss Anstruther's Letters, which was published in 1942.
Macaulay was never a simple believer in "mere Christianity"; however, and her writings reveal a more complex, mystical sense of the Divine. That said, she did not return to the Anglican church until 1953; she had been an ardent secularist before and, while religious themes pervade her novels, previous to her conversion she often treats Christianity satirically, for instance in Going Abroad and The World My Wilderness. She never married, as a result of her lengthy and secret relationship with Gerald O'Donovan.
The Towers of Trebizond, her final novel, is generally regarded as her masterpiece. Strongly autobiographical, it treats with wistful humour and deep sadness the attractions of mystical Christianity, and the irremediable conflict between adulterous love and the demands of the Christian faith. For this work, she received the James Tait Black Memorial Prize in 1956.
She was created a Dame Commander of the Order of the British Empire (DBE) on 31 December 1957 in the 1958 New Years Honours. Macaulay was an active feminist throughout her life. Dame Rose Macaulay died on 30 October 1958, aged 77.