She gained an international following as the primary founder of Theosophy as a belief system. Born into an aristocratic family in Yekaterinoslav , Blavatsky traveled widely around the empire as a child. Largely self-educated, she developed an interest in Western esotericism during her teenage years. According to her later claims, in she embarked on a series of world travels, visiting Europe, the Americas, and India. She also claimed 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 a deeper understanding of the synthesis of religion, philosophy, and science.
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 s, 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 , she befriended Henry Steel Olcott and rose to public attention as a spirit medium, attention that included public accusations of fraudulence. In , she published Isis Unveiled , a book outlining her Theosophical world-view. Associating it closely with the esoteric doctrines of Hermeticism and Neoplatonism , Blavatsky described Theosophy as "the synthesis of science, religion and philosophy", proclaiming that it was reviving an "Ancient Wisdom" which underlay all the world's religions.
In , she and Olcott moved to India, where the Society tried to make allies to the Arya Samaj , a Hindu reform movement. That same year, while in Ceylon , she and Olcott became the first people from the United States to formally convert to Buddhism. Although opposed by the British colonial administration, Theosophy spread rapidly in India but experienced internal problems after Blavatsky was accused of producing fraudulent paranormal phenomena.
In ailing health, in she returned to Europe, establishing the Blavatsky Lodge in London. There she published The Secret Doctrine , a commentary on what she claimed were ancient Tibetan manuscripts, as well as two further books, The Key to Theosophy and The Voice of the Silence.
