Marie Sinclair, Countess of Caithness

Marie Sinclair, Countess of Caithness (1830 – 2 November 1895), formerly Marie (or Maria) de Mariategui, was a British aristocrat of Spanish descent who married, as his second wife, James Sinclair, 14th Earl of Caithness. She is particularly remembered for her interest in spiritualism and Theosophy and her association with Helena Petrovna Blavatsky, whose occult successor she claimed to be.

Theosophical Society involvement

Lady Caithness became active in the Theosophical Society in New York in 1876 shortly after it was formed, although her official date of joining was 1 February 1883, according to membership records at Adyar. A wealthy dowager, she supported the Theosophical Society financially. She was crucial to the development of the Theosophical movement in France where she founded the Société Théosophique d'Orient et d'Occident on 28 June 1883 and served as its president. Among her writings was The Mystery of the Ages; Contained in the Secret Doctrine of All Religions, published in 1887.

Writings

• Old Truths in a New Light, or, An earnest endeavor to reconcile material science with spiritual science and with Scripture. London: Chapman and Hall, 1876.
• Serious Letters to Serious Friends. London: Trubner & Co, 1877. Second edition available at Hathitrust, 341 pages.
• La théosophie universelle: théosophie Bouddhiste. Paris: Georges Carré, 1886.
• The Mystery of the Ages; Contained in the Secret Doctrine of All Religions, London, 1887. Fourth edition available at Hathitrust, 541 pages.
• A Midnight Visit to Holyrood. London: C.L.H. Wallace, 1887. Available at Google Books.
• Théosophie sémitique; Les vrais israélites: l'identification des dix tribus perdues avec la nation britannique; Les suffis et la théosophie mahométane. Paris: Libr. G. Carré, 1888.
• Je me suis éveillé: Conditions de la vie de l'autre côté, communiqué par écriture automatique. Paris: Rédaction et administration de l'"Aurore"', 1895. Accounts of life after death, communicated by automatic writing.