On taking possession of Sissinghurst Castle in 1930, Vita Sackville-West’s first step was to create an airy writing room on the first floor of the Tower. Her husband, Harold Nicolson, claimed a cosier space on the ground floor of nearby South Cottage. The working libraries of two prolific authors, both rooms are to this day still filled with their books. Each collection is powerfully expressive of personality: Harold favoured political, social and literary history, while Vita prioritised poetry, gardening and travel alongside the works of contemporary writers. Sexuality was a subject of equal interest to both partners, and it is no surprise to find that they maintained a well-stocked bookshelf dedicated to sex and psychology.

Vita and Harold’s open marriage has been explored in countless books, examining its impact on their families, their writing and the gardens they created at Long Barn and Sissinghurst. Less attention has been paid to the way that their sexuality shaped the homes they shared and to the complex choreography of their queer domesticity. Separate living helped the couple maintain a happy marriage alongside many same-sex relationships. Harold worked in London during the week, sharing his life with a series of younger men. Vita’s female lovers stayed at Sissinghurst while Harold was away, tactfully departing on Saturday mornings.

Although the sex and psychology collection is located in Vita’s Tower, annotations reveal a shared enthusiasm for the subjects. Harold and Vita acquired the full six-volume set of Studies in the Psychology of Sex by Dr Henry Havelock Ellis. The second volume, Sexual Inversion, was the first medical textbook on homosexuality and was banned for obscenity shortly after it came out in Britain in 1897. The Nicolsons bought their copy from the American publisher F A Davis in 1923. Vita’s initials appear at the front. The endpaper is inscribed by Harold with a personalised version of a quotation from Verlaine’s Confessions: ‘On est fier quelquefois quand on se compare.’

Roughly translated as ‘We are proud sometimes when we compare ourselves’, the quotation signals Harold’s confidence in the way that he and Vita had adapted their marriage to allow the inclusion of other sexual partners. And it acknowledges Vita’s role in encouraging Harold to publish a life of Verlaine in 1921. Verlaine was a celebrated French decadent poet, but he was also notorious for his affair with the youthful Arthur Rimbaud. Together they wrote the ‘Sonnet du Trou du Cul’, an erotic poem in honour of the anus.

Modern critics have censured Harold for skating over Verlaine’s bisexuality and for employing a similar reticence in his later studies of three other sexually ambiguous writers, Byron, Tennyson and Swinburne. But Harold was writing at a time when homosexuality was still illegal in the UK. Sexual openness at home was difficult to mirror in public when faced with the threat of prosecution. The brave author of another book on Vita and Harold’s shelf, Edward Carpenter, lived openly with his lover George Merrill at Millthorpe in Derbyshire and campaigned for a more inclusive understanding of gender.

Carpenter’s book The Intermediate Sex appealed to Vita, who had wandered the streets of Paris dressed as ‘Julian’ and adopted a uniform of whipcord breeches and high laced boots once she moved to Sissinghurst. The cover of her copy is annotated ‘Middlesex’, reflecting her conviction that over time men and women would grow to resemble one another and same-sex love would become more accepted. Virginia Woolf expressed similar feelings in Orlando, where the hero/heroine evades gender categorisation, changing as the centuries progress.

The dedication copy of Orlando, Woolf’s tribute to Vita, sat in the latter’s writing room alongside twenty-three other copies of Woolf’s works. Vita filled her room with relics of other past lovers. Every object carries an associative memory: crystal rabbits from Violet Trefusis, paintings by Mary Campbell, illuminated manuscripts produced by Chris St John (the name adopted by Christabel Marshall), embroideries worked by Gwen St Aubyn. Some objects come with double layers of meaning. A copy of the 1886 edition of Lewis Carroll’s Alice’s Adventures Under Ground is inscribed ‘Ellen Terry from the Author, Jan 1887’, and was presented to Vita by the artist Clare Atwood. Clare assumed the name Tony, and lived in happy partnership with Terry’s daughter Edy Craig and Chris St John at Smallhythe Place until 1932, when Chris was distracted by passion for Vita.

Chris and Tony both adopted distinctive identities, not only choosing male first names but also opting for a more masculine style of dress. They were friends of Radclyffe Hall and her lover Una Troubridge, and they joined the ranks of her supporters after The Well of Loneliness was prosecuted for obscenity in 1928. Tony painted an androgynous portrait of Vita as Portia from The Merchant of Venice, wearing the lawyer’s costume she dons in the court scene. Chris wrote for the feminist journal Time and Tide and produced a biography of Dr Christine Murrell, the first female doctor elected to the General Medical Council.

Both Chris and Tony would have been familiar with other popular titles on Vita and Harold’s well-stocked sex and psychology bookshelf: Otto Weininger’s Sex and Character, Russell Thacher Trall’s Sexual Physiology and Hygiene and multiple works by Gerald Heard. Financially supported by his lover Christopher Wood, Heard produced works of popular science that linked parapsychology with meditation and alternative understandings of consciousness. These were subjects that would prove as appealing to later writers, such as Christopher Isherwood and Timothy Leary, as they were to the residents of Sissinghurst. r