Koot Hoomi is said to be one of the Mahatmas that inspired the founding of the Theosophical Society in 1875. In Theosophy it is believed that he engaged in a correspondence with two English Theosophists living in India, A. P. Sinnett and A. O. Hume, which correspondence was published in the book The Mahatma Letters to A. P. Sinnett.

Alfred Percy Sinnett was an English author and theosophist.