Blavatsky Helena Petrovna Hahn

Bla·vat·sky

 (blə-văt′skē, -vät′-), Helena Petrovna Hahn 1831-1891.
Russian-born theosophist who founded (1875) the Theosophical Society in New York City and wrote books of occult lore, such as Isis Unveiled (1877).