Most early Wiccan groups adhered to the duotheistic worship of a Horned God of fertility and a Mother Goddess, with practitioners typically believing that these had been the ancient deities worshipped by the hunter-gatherers of the Old Stone Age, whose veneration had been passed down in secret right to the present. This theology derived from Egyptologist Margaret Murray's claims about the witch-cult in her book "The Witch-Cult in Western Europe" published by Oxford University Press in 1921; she claimed that whereas the cult as recorded in the Early Modern witch trials had venerated a Horned God, centuries before it had also worshipped a Mother Goddess. This duotheistic Horned God/Mother Goddess structure was embraced by Gardner – who claimed that it had Stone Age roots – and remains the underlying theological basis to his Gardnerian tradition. Gardner claimed that the names of these deities were to be kept secret within the tradition, although in 1964 they were publicly revealed to be Cernunnos and Aradia; the secret Gardnerian deity names were subsequently changed.