Who wrote Wide Sargasso Sea, the prequel to Jane Eyre?

Jean Rhys, in 1966, and it is one of the great acts of literary answering-back. Jane Eyre has a madwoman locked in the attic - Bertha Mason, Rochester's Creole first wife, who is barely a person in the novel and functions as an obstacle and a horror. Rhys gave her a childhood, a name, Antoinette, and a case.

The novel is set in Jamaica and Dominica after the abolition of slavery, and the madness is constructed rather than innate: the family is despised by the formerly enslaved as ex-owners and by the English as colonials, the marriage is arranged for money, and Rochester renames her Bertha, which is presented as an act of erasure. She is mad by the end because of what has been done to her, and the last section is her in the attic in England, cold and displaced.

Rhys had published four novels in the 1930s and then disappeared so completely that she was widely assumed dead - she was living in obscurity in Cornwall and Devon, and was rediscovered when a BBC adaptation of one of her books prompted a search for her. Wide Sargasso Sea came out when she was 76, after nine years of work, and made her famous. She said it had come too late, and that if it had happened when she was young it would have been a pleasure.