Mouni Sadhu was the pen name of Mieczyslaw Demetriusz Sudowski, an author of mystical and esoteric subjects.
Although born in Poland, he eventually became an Australian citizen. As a writer his subject matter concerned Western Hermeticism, and the Yoga tradition of India. In these his two greatest personal influences were the Russian esotericist G.O. Mebes and Ramana Maharshi, respectively. The name "Mouni Sadhu" means "silent (mouni) holy man (sadhu)" in Sanskrit.
His literary estate was left to the Australian Society of Authors, of which he was a member. The royalties that have accrued from the estate now provide for services to Australian Authors.
Hard and fast information about Sadhu's early life is hampered by the fact that the author was often to reluctant to speak about his background. Also, different commentators have furnished conflicting accounts of his early life, whilst furnishing very little in the way of evidence.
According to Sadhu's own application for Australian citizenship, he claimed to have being born in Warsaw, Poland. He married, in 1933, a Catherine Gunt, who died six years later in a bomb-attack coinciding with the outbreak of World War Two. Between September and November 1939, he was a prisoner of war in the USSR. From then until 1945 he was a prisoner of war in Germany. He was released in 1945 and served with the US Army in France until November 1946.
Between 1946 and 1948 he lived for two years in Brazil, before emigrating to Australia. In 1949, he spent five months in India (see below). Sadhu gave his occupation as "electrical mechanic," and "part-time writer."
As a young man in Europe, from 1926 to 1933, Sadhu belonged to an order of Rosicrucian Hermetists and published a number of books on Tarot and the occult.
In 1949, Sadhu spent several months at the ashram of Ramana Maharshi in Tiruvanammalai near the Arunachala hill, India, where he studied Advaita Vedanta. He described this experience in his book "In Days Of Great Peace." Sadhu claimed that his contact with Ramana caused him to attain nirvikalpa samadhi. In almost all of Sadhu's subsequent books, he paid tribute to Ramani Maharshi as the "last of the Great Indian sages." After he moved to Australia, he established a group of Maharshi devotees, but his abiding interest in occultism led the Australian group to part ways with the Indian ashram.