Helena Petrovna Blavatsky (1831–91), writer, traveller and spiritualist, is well known for her role in nineteenth-century theosophy. Born in the Ukraine, Blavatsky travelled extensively and claimed to have spent seven years studying esoteric mysteries in Tibet. From 1863 she began working as a medium and later counted W. B. Yeats among her followers. In 1875 she founded the Theosophical Society with Henry Steel Olcott. Influenced by Eastern philosophy and the Templars, Freemasons and Rosicrucians, the Society aimed to unravel the occult mysteries of nature. First published in 1877, this book outlines theosophy's precepts. The book is a mishmash of Hermetic philosophy, Christian history and Asian theology, and was allegedly dictated astrally from authorities including Plato, Solomon and Roger Bacon.