Writer, artist, visionary and priestess of goddess Isis

Olivia Melian Durdin-Robertson, who has died aged 96, was a writer, artist, visionary and priestess of Isis, who through her family's social and cultural connections provided a link with the hermetic spiritualist tradition of the Celtic Twilight, as exemplified particularly by George Russell ("AE") and WB Yeats.

The second of the four children of Norah (née Parsons) and Manning Robertson, she was born in London, where her father, an architect and town planner, worked for the ministry of health. In 1925, the Robertsons left Surrey and returned to their Irish ancestral home. Manning Robertson practised architecture, advocated social housing and town planning, and wrote prolifically and critically as Ireland’s first serious commentator on 20th-century architecture, while the family spent holidays at their family home, Huntington Castle, Clonegal, on the Carlow-Wexford border. The young Olivia was introduced to the “magic of the sidhe” through the mysterious “aged hermit” Mr Fox, who lived on a hallowed site beside the river Slaney.

When Yeats died in 1939, his widow asked Robertson to design the poet’s headstone at Drumcliff, Co Sligo. Many years afterwards Olivia told an interviewer: “My father designed Yeats’s tombstone, which carried the inscription ‘Cast a cold eye / On life, on death. / Horseman, pass by.’ Later my mother met Mrs Yeats and asked her if she liked the tombstone, and she said ‘Yes, and Willie’s delighted too!’”

Olivia Robertson studied at Heathfield School in Ascot and the Grosvenor School of Modern Art. She worked as a volunteer nurse in England during the second World War, returning to Dublin to study history of European painting at University College, Dublin, in 1943. She spent four years working with Dublin Corporation's enlightened inner-city playground scheme, drawing portraits of children which would feature as spontaneous, spirited line illustrations in her books: St Malachy's Court (1946), Field of the Stranger (1948), The Golden Eye (1949), Miranda Speaks (1950), It's an Old Irish Custom (1954) and The Dublin Phoenix (1957), all full of shrewdly observed evocations of the city.

In 1946, she received her first awakening into what she termed “the eternal reality . . . the source of our being and all that we hold to be good, noble and true” from the Egyptian goddess Isis. But it was not until 1960 that she joined her brother, Lawrence, a former Anglican rector and his wife, Pamela, who had decided to settle in their “land of heart’s desire” at Huntington Castle.

First they formed the philanthropic Clonegal Local Welfare scheme , then in 1963, their Centre for Meditation and Study. Regular seminars, esoteric site visits and discussions explored the inner meanings of the altered states of consciousness they had each experienced.

In the early 1970s she and her brother, she told an interviewer in 1992, "became aware of the imbalance in the world . . . Suddenly I realised the missing factor was the total ignorance of, and deliberate attack on the religion of God the Mother."

Band of followers

The siblings sought the divine through comparative study, harmony with nature and creation, and a positive, instinctive, all-embracing new symbolic order. This led to Lawrence Durdin-Robertson's The Cult of the Goddess (1974), Olivia's autobiographical book The Call of Isis (1975), their formation of the Fellowship of Isis in 1976 and Olivia's permanent return to Ireland.

Robinson attracted a growing band of followers through the colourful blend of rituals, liturgy, images and words she evolved in her mediation with the universal goddess. At Huntington Castle she and Lawrence built a temple in the dungeon with 12 shrines and five chapels, each dedicated to a particular goddess.

Over 40 or so years, she wrote a succession of booklets, illustrated by her drawings as the fellowship became multireligious, multicultural and multinational. In 1993, her travels included her representation of the fellowship at the World Parliament of Religions in Chicago, where she breakfasted with the Dali Lama.

She continued to write, paint, discuss, give presentations and meditations, travelling indefatigably until recently, when a fall in the castle grounds curtailed her activities. She died peacefully in Wexford, one of the last living links with the esoteric mysticism of AE and Yeats.