In 1966, William was initiated by Taliesin einion Vawr into the Welsh Tribe of Dynion Mwyn, "The Gentle Folk", near Betws-y-Coed, in North Wales. He was given the name Rhuddlwm Gawr by the elders of the Dynion Mwyn tradition, and told that he was to return to the United States and begin to teach the Craft of Y Tylwyth Teg (the Clan of "The Fairy Folk"). After returning to the United States, he worked on NASA's Apollo Manned Lunar Project. He began teaching a Witchcraft class in a small Houston bookstore.