As a form of Western esotericism, the New Age movement drew heavily upon a number of older esoteric traditions, in particular those that emerged from the occultist current that developed in the eighteenth century. Such prominent occult influences include the work of Emanuel Swedenborg and Franz Mesmer, as well as the ideas of Spiritualism, New Thought, and the Theosophical Society. A number of mid-twentieth century influences, such as the UFO religions of the 1950s, the Counterculture of the 1960s, and the Human Potential Movement, also exerted a strong influence on the early development of the New Age movement. Although the exact origins of the movement remain contested, it is agreed that it developed in the 1970s, at which time it was centred largely in the United Kingdom. It expanded and grew largely in the 1980s and 1990s, in particular within the United States.