His biography of Isabelle de Charrière entitled The Portrait of Zelide won the 1925 James Tait Black Memorial Prize.
Lady Sybil was the youngest daughter of Irish peer and barrister, Hamilton Cuffe, 5th Earl of Desart, who served as the last Lord Lieutenant of Kilkenny, and his wife, Lady Margaret Joan Lascelles, a daughter of Henry Lascelles, 4th Earl of Harewood.
[3] She had arrived in Florence when her first husband, terminally ill with tuberculosis, had written he wanted their young daughter, Iris, to grow up in Italy, "free from all this national feeling which makes people so unhappy.
There she formed a close friendship with Bernard Berenson at the nearby I Tatti, and seasonal resident Lady Cecilia Pearse.
At the time of his death, of pneumonia in New York City, Geoffrey Scott had been retained as an editor of the papers of James Boswell.