The Triumph of the Moon: A History of Modern Pagan Witchcraft, published in 1999, is Hutton's best known work and the book that settled, for most scholars, the historical status of Wicca. Working from primary sources rather than the movement's own founding legends, Hutton traced modern Pagan Witchcraft to a twentieth century synthesis assembled by Gerald Gardner out of ceremonial magic, Freemasonry, folklore revivalism and Margaret Murray's witch-cult thesis, rather than to an unbroken pre-Christian survival as Wicca's own foundation stories had long claimed. The book also traced the wider currents, from Romanticism through the occult revival, that made such a synthesis possible in Gardner's England, giving Wicca a real history in place of an invented one.
Hutton's companion study, The Stations of the Sun, published in 1996, performed a similar service for the British ritual year, tracing customs popularly assumed to be pre-Christian survivals, from Halloween to May Day, to their actual and often much later documented origins. Together the two books established Hutton as the leading academic authority on the history of British Paganism and folklore, work he has extended in subsequent studies of shamanism, the druids and the witch trials, consistently applying the same discipline: separate what the sources actually show from what later communities have wanted to believe.