Gwen John’s first achievement as a painter was not a picture but a departure. Alicia Foster’s Gwen John: Art and Life in London and Paris – which is being published to coincide with a major exhibition of the artist’s work at the Pallant House Gallery in Chichester – opens not with her birth but with her move, at nineteen, from Tenby in Wales to London, where she enrolled at the Slade School of Fine Art in 1895. Foster suspects that John managed to get permission from her father for this grand escape by making plans to attend a finishing school, before switching courses at the last minute. Her younger brother Augustus had already been a student at the Slade for a year.

John’s first room was near Euston – not an especially respectable area, but varied and close to the British Museum, and not far from the National Gallery. London’s population had grown sixfold over the preceding century, making it a place where you could go unnoticed if you wanted to, but John was soon living in a boarding house crammed with Slade students. Her watercolour Portrait Group suggests a lively, industrious home that allowed for an unusual degree of mixing between the sexes.

After travelling to France on a walking trip in 1903, she spent the next seven years living in Montparnasse, mostly alone. (Even once she’d moved out to Meudon, a popular beauty spot with views over the city, she kept a studio in Paris.) Eventually settling in a road