The Gardners resided in the New Forest area, where Gardner became active with the Fellowship of Crotona, an occult group linked to Co-Masons, a Masonic order founded by Mrs. Besant Scott, daughter of Theosophist Annie Besant.
This group had established “The First Rosicrucian Theater in England,” which showcased plays with occult themes.
One member revealed to Gardner that they had shared a past life and described a location in Cyprus that Gardner had dreamt about.
Within the Fellowship of Crotona was a secretive group that trusted Gardner with their secrets.
These members claimed to be hereditary Witches, practicing a Craft passed down through generations, untouched by the witch hunts of the Middle Ages and Renaissance.
The group convened in the New Forest.
Just before World War II began in 1939, Gardner was initiated into the coven at the home of Old Dorothy Clutterbuck.
Gardner had a deep interest in magic and witchcraft, dedicating much time to expanding his network in the occult community.
He gathered material on magical practices, especially ceremonial magic, which he compiled into an unpublished manuscript titled Ye Bok of ye Art Magical.
In 1946, he met Cecil Williamson, the founder of the Witchcraft Research Centre and Museum of Witchcraft.
In 1947, he was introduced to Aleister Crowley by Arnold Crowther.
Gardner was particularly keen on learning from Crowley, who was in poor health and only months away from death.
Gardner acquired magical material from Crowley.
Using this and other sources, he compiled his book of shadows, a collection of rituals and Craft laws.
Gardner claimed to have received a fragmentary book of shadows from his New Forest coven.