was a writer, and the eldest child of The 4th Marquess of Dufferin and Ava and the brewery heiress Maureen Guinness.

A well-known figure in the literary world through her journalism and her novels, Lady Caroline Blackwood was equally well known for her high-profile marriages, first to the artist Lucian Freud, then to the composer Israel Citkowitz and finally to the poet Robert Lowell, who described her as "a mermaid who dines upon the bones of her winded lovers". Her novels are known for their wit and intelligence, and one in particular is scathingly autobiographical in describing her unhappy childhood.

She was born into an Anglo-Irish aristocratic family from Ulster at 4 Hans Crescent in Knightsbridge, her parents' London home. She was, she admitted, "scantily educated" at, among other schools, Rockport School (County Down) and Downham (Essex). After a finishing school in Oxford she was presented as a debutante in 1949 at a ball held at Londonderry House.