FOR too long, tonal restrictions in Gwen John’s (1876-1939) paintings have been erroneously read as a metaphor for a thwarted life and artistic career. This is the premise of Alicia Foster’s “Gwen John: Art and Life in London and Paris” at Pallant House, repositioning the Tenby-born artist at the heart of modern art. A magnified, black-and-white photographic panel of John life-modelling in Rodin’s studio, in the centre of the main gallery, dispels any notion of a wallflower.

Beginning with a pencil-and-sepia wash sketch of the artist at an easel, Gwen John and Frederick Brown (1895-8) by her younger brother Augustus, the exhibition takes us from John’s turn-of-the-century training at the Slade (part of the “Godless institution on Gower Street” founded to offer university education to non-Anglicans) to her life in Paris until the Second World War.

Living around Euston and Fitzrovia, sharing lodgings with Augustus, John inhabited a milieu resembling Joseph Conrad’s The Secret Agent, with a flotsam of refugees, anarchists, and students flowing through cheap rooms in central London. The novel excitement of young men and women living and studying together is captured in Portrait Group (1898), a watercolour-and-pencil interior showing Augustus leaning on a mantlepiece, her sister Winifred seated at table with the student Michael Salaman, and possibly John herself leaning by the window.

© Musée RodinGwen John (1876-1939), Autoportrait à la Lettre (Self-Portrait with a letter) (c.1907-9), pencil and Watercolour

In 1904, John settled permanently in Paris, believing that the independence enjoyed at the Slade, as she travelled alone and attended galleries to copy from the Old Masters, was unlikely to extend beyond student days. To support herself, she modelled, and worked at the studio of Auguste Rodin, posing for the memorial to James McNeil Whistler. John and Rodin became lovers, and, through the sculptor, she met the poet Rainer Maria Rilke, and learned of Cézanne’s work.

Witnessing Rodin making life drawings shaped John’s own work. But it was interiors that preoccupied John in this period, as she sent her paintings back to London to be shown at the New English Art Club. In Paris, the Peintres d’Intérieurs exhibited in 1905, and John was part of this scene, which included Pierre Bonnard and Edouard Vuillard.

Becoming a Roman Catholic in 1913, John was one of many Parisian British to do so, joining the Catholic revival sweeping France in the early 20th century. A portrait of Chloë Boughton-Leigh (1910) shows John’s friend in a simple blue dress, wearing a delicate pendant, hair loosely pinned up, with tendrils falling down, gazing at the viewer in shrewd assessment. Boughton-Leigh became a Roman Catholic three years after John. The portrait was sent to the artist’s new patron in New York, the Modernism collector John Quinn, who wrote: “I think it is finer than anything of that kind that Whistler ever did.”

John’s work was exhibited at the 1913 Armoury Show in New York, and Quinn’s patronage enabled her to move to the suburb of Meudon, where Rodin had a home and studio, while also keeping her studio in central Paris. Her Meudon neighbours, an order of Dominican nuns, commissioned a painting of Mère Marie Poussepin, who founded the Dominican Sisters of Charity at the end of the 17th century. The order received formal recognition in 1897.

© Yale Center for British Art, Paul Mellon CollectionGwen John (1876-1939), La Chambre Sur la Cour (c.1907-08), oil on canvas

The 1911 tiny black-and-white prayer card that John used as source material is on display, together with two of the series of six portraits which she made of Mère Marie. In both paintings, the seated nun’s voluminous dark-grey and white habit contrasts with the plain beige-brown background, where she casts a foreshortened shadow. The folds of her sleeves are more shaded in one version, suggesting movement. A full white headdress, echoing the treatment of the sleeves, frames a radiant face. John considered these portraits from imagination some of her best work.

Before her formal reception into the RC Church, the artist began to merge faith and modern art in works including A Lady Reading (1909-11), in which a young woman, head copied from Dürer’s depiction of the Virgin, stands holding a book in a contemporary interior, with light-filled red and white curtains blowing towards her. John did a second version of this recreation of the Annunciation, with her own face on the female figure.

“Gwen John: Art and Life in London and Paris” is at Pallant House Gallery, 9 North Pallant, Chichester, until 8 October. Phone 01243 774557. pallant.org.uk