Helena Petrovna Blavatsky (Russian: , Yelena Petrovna Blavatskaya; 12 August [O.S. 31 July] 1831 – 8 May 1891) was an occultist, spirit medium, and author who co-founded the Theosophical Society in 1875. She gained an international following as the leading theoretician of Theosophy, the esoteric movement that the Society promoted.
Born into an aristocratic Russian-German family in Yekaterinoslav, Ukraine, Blavatsky traveled widely around the Russian Empire as a child. Largely self-educated, she developed an interest in Western esotericism during her teenage years. According to her later claims, in 1849 she embarked on a series of world travels, visiting Europe, the Americas, and India. She alleged that during this period she encountered a group of spiritual adepts, the "Masters of the Ancient Wisdom", who sent her to Shigatse, Tibet, where they trained her to develop her own psychic powers. Both contemporary critics and later biographers have argued that some or all of these foreign visits were fictitious, and that she spent this period in Europe. By the early 1870s, Blavatsky was involved in the Spiritualist movement; although defending the genuine existence of Spiritualist phenomena, she argued against the mainstream Spiritualist idea that the entities contacted were the spirits of the dead. Relocating to the United States in 1873, she befriended Henry Steel Olcott and rose to public attention as a spirit medium, attention that included public accusations of fraud . . . more