‘I do love you as much as I’m capable of loving anyone,’ the photographer Barbara Ker-Seymer (1905–93) told her most enduring lover, the American-Guyanese sculptor Barbara Roett. Despite there being a 22-year age gap between them, Ker-Seymer spent the last forty years of her long life in a happy relationship with Roett.

Somewhat improbably, Ker-Seymer and Roett ran one of London’s first launderette services. The decision to become a businesswoman, a career choice which few Englishwomen made in the 1950s, was fuelled by Ker-Seymer’s need for a steady income. ‘Bar’, as she was always known to her friends, had no money of her own and needed to support a young son until his absent father, John Rhodes, finally consented to the provision of maintenance. Society photography, the form of work for which she had been haphazardly trained by Olivia Wyndham, never made Bar rich and custom dried up in the postwar years. Visitors to the laundromats had no idea that they were owned by a former queen of bohemian London, admired by Man Ray and Jean Cocteau and her first supporter, Paul Nash, as the city’s coolest photographer.

Entertainingly chronicled by Sarah Knights, Ker-Seymer’s life followed an unpredictable and often rackety course. Her father, Vere, was a spendthrift itinerant who thought nothing of waking his small daughter for a dawn game of poker or robbing her money box to pay for a taxi. Ker-Seymer was seven