Gwyneth Johnstone was a daughter of Augustus John and the niece of Gwen John - two of the most prominent British painters of the 20th century - and was herself a gifted artist.
She was born in late 1914, but always kept her date of birth a secret. Her mother, the musician Nora Brownsword, had been seduced by Augustus John when posing for him shortly before the First World War.
Mother and daughter were to be inseparable, the artist Julian Trevelyan affectionately referring to them as "The Cave Women" in tribute to their disregard of everyday conventions. But Gwyneth - brought up in London and Norfolk - had a remote relationship with her father.
Gwyneth struggled in her early studies at the Slade School of Fine Art and then with the Cubist painter André Lhote in Paris. But at one point she felt able to share a London studio with her father, and he painted her likeness in a remarkable portrait . For many years she had a base at the village of Ramatuelle behind St Tropez, and that sunny landscape sustained her art (which she often reworked at her homes in London and Norfolk) until she bought a house in Spain, in the hills above Benidorm.
Her themes were, and remained, shepherds, fishermen and lovers at ease in wild Mediterranean landscapes . Her sheep and cattle seem to be engaged in a dance in the fertile spaces between folds of cliffs, hills and mountains . Her pictures, which she called "romantic modern landscapes", convey an innocent happiness . She finally hit her creative stride, painting as she wished and what she loved, after lessons in the 1950s with Cecil Collins, another maker of magical, dreamlike landscapes, and after studying the work of Christopher Wood and Paul Klee.
She showed in mixed exhibitions with Young Contemporaries, the London Group and the Women's International Art Club, of which she was president for a time. There were well-received solo shows from Spain to Los Angeles, in several London galleries (Portal, Sally Hunter, Michael Parkin, Patrick Searle), and a sell-out display at Norfolk's School House Gallery as late as 2007.