Wicca
Some time from 1945 to 1949, Gerald Gardner changed, and added content to, the rituals of an earlier group, called the New Forest Coven. In so doing, Gerald Gardner created Wicca. The many elements from the grimoire (old hand-written book) called the Key of Solomon are present in Wicca. Those are also in Gardner's 1949 book, High Magic's Aid, and were most likely added by Gardner himself, rather than by the New Forest Coven that came before him.