Dion Fortune (December 6, 1890 - 1946), born Violet Mary Firth, was a British occultist and author who was born at Bryn-y-Bia in Llandudno, Wales. Her pseudonym was inspired by her family motto "Deo, non fortuna" (which translates as "God, not fate").
She reported visions of Atlantis at age four and the developing of psychic abilities during her twentieth year. She attended courses in psychology and psychoanalysis at the University of London, and became a lay psychotherapist at the Medico-Psychological Clinic in Brunswick Square.
Her first magical mentor was the Irish occultist and Freemason Theodore Moriarty. In 1919 she was initiated into the London Temple of the Alpha et Omega before transferring to the Stella Matutina order.
She wrote a number of novels and short stories that explored various aspects of magic and mysticism, including The Demon Lover, The Winged Bull, The Goat-Foot God, and The Secrets of Dr. Taverner. This latter is a collection of short stories based on her experiences with Theodore Moriarty. Two of her novels, The Sea Priestess and Moon Magic, became influential within the religion of Wicca, especially upon Doreen Valiente.
Of her non-fictional works on magical subjects, the best remembered of her books are; The Cosmic Doctrine, meant to be a summation of her basic teachings on mysticism, The Mystical Qabalah, an introduction to Hermetic Qabalah, and Psychic Self Defence, a manual on how to protect one's self from psychic attacks. Though some of her writings may seem dated to contemporary readers, they have the virtue of lucidity, and the avoidance of the deliberate obscurity that characterised many of her forerunners and contemporaries.
In 1922, after a falling out with Moina MacGregor Mathers and with Moina's consent, Dion Fortune left the Alpha et Omega and formed the Fraternity of the Inner Light as an offshoot of the Alpha et Omega. This brought new members to the Alpha et Omega. Fortune's group was later renamed "The Fraternity of the Inner Light", and was, later still, renamed "The Society of the Inner Light". This society was to be the focus of her work for the rest of her life. Her masterpiece, The Mystical Qabalah was first published in England in 1935, eleven years before her death from leukemia.
Dion Fortune met and corresponded with Aleister Crowley, whom she acknowledged in the introduction of The Mystical Qabalah.
Dion Fortune claims to have participated in the "Magical Battle of Britain", which was an attempt by British occultists to magically aid the war effort and which aimed to forestall the impending German invasion during the darkest days of World War II. The effort involved in this endeavour is said to have contributed to her death shortly after the war ended. Her Society of the Inner Light continues to function.