My friend Jill Longmate, who has died of cancer aged 63, was a writer, poet and historian, and the author of the celebrated, finely researched book From the Closet to the Screen: Women at the Gateways Club 1945-85.

For decades the Gateways, a dingy basement off Kings Road, Chelsea, was the only place in London where lesbians could meet and be themselves. Dusty Springfield, Patricia Highsmith, Maggi Hambling and Sandi Toksvig all went there, as did I. The club was the setting for Maureen Duffy’s 1966 novel The Microcosm and was depicted in the 1968 Hollywood movie The Killing of Sister George.

I first met Jill at the Foyles’ launch of her book in 2003. She published it under the pseudonym Jill Gardiner, out of deference to her parents who disdained the subject matter. Her mother, Elizabeth (nee Taylor), was a deputy head teacher, her father, Norman Longmate, a social historian. “He had mistresses. She had God,” Jill wrote of them.

Jill was born in Kingston upon Thames, south London, and went to Richmond county school for girls. Like her mother, Jill read history at Somerville College, Oxford, then taught. She was head of politics at Haywards Heath College in the 1990s, wrote Women and Politics: Progress without Power? (1997) for the Politics Association and acquired a clutch of other degrees.

Only after she settled in Brighton in 1983 did she feel able to be openly lesbian, immersing herself in the local scene. In 1992 she co-edited Daring Hearts: Lesbian and Gay Lives of 50s and 60s Brighton.

Though Jill chronicled the lives of contemporary lesbians, her persona was Bloomsbury. Even indoors she wore a trademark wide-brimmed hat of the Vita Sackville-West sort – she was seldom seen bareheaded. She kept a daily diary, her emails to friends were the length of old-fashioned letters and Charleston was a favoured literary festival. She became chair of Brighton Poets in 1994.

Her own love poems, With Some Wild Women: Poems 1989-2019, are romantic, whimsical and wayward.

At the time of her death Jill was well into the writing of a biography of Duffy – with Maureen’s cooperation. This unfinished work will be housed at King’s College London. Jill’s Gateways research will go to the Bishopsgate Institute in London and her personal papers will be held at the Keep, a historical resource centre in Brighton. Her wide-brimmed floppy hat went with her into her grave.

A legion of female friends became Jill’s cherished family. She is survived by her partner of 31 years.