Sri Nisargadatta Maharaj (birth name: Maruti Shivrampant Kambli) (April 17, 1897 – September 8, 1981) was an Indian spiritual teacher and philosopher of Advaita (Nondualism), and a Guru, belonging to the Ichegeri branch of the Navnath Sampradaya.
One of the 20th century’s exponents of the school of Advaita Vedanta philosophy (nondualism), Sri Nisargadatta, with his direct and minimalistic explanation of non-dualism, is considered the most famous teacher of Advaita since Ramana Maharshi.
In 1973, the publication of his most famous and widely-translated book, I Am That, an English translation of his talks in Marathi by Maurice Frydman, brought him worldwide recognition and followers.
From Wikipedia