The Theosophical Society is an organization formed in 1875 to advance the spiritual principles and search for Truth known as Theosophy

Theosophy

Theosophy, in its modern presentation, is a spiritual philosophy developed since the late 19th century. Its major themes were originally described mainly by Helena Blavatsky , co-founder of the Theosophical Society...

. The original organization, after splits and realignments has several successors. Theosophy is an active philosophical school today, and through a process of schism has also given rise to other mystical, philosophical and religious beliefs and organizations.
The Theosophical Society was officially formed in New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

, United States, in November 1875 by Helena Blavatsky, Henry Steel Olcott

Henry Steel Olcott

Colonel Henry Steel Olcott was an American military officer, journalist, lawyer and the co-founder and first President of the Theosophical Society....

, William Quan Judge

William Quan Judge

William Quan Judge was a mystic, esotericist, and occultist, and one of the founders of the original Theosophical Society. He was born in Dublin, Ireland. When he was 13 years old, his family emigrated to the United States...

 and others.