Painter and draughtsman Charles W. Fliess was born Konrad Wilhelm Fleiss into a family probably of Jewish origin in Berlin, Germany in 1899, the son of the controversial otolaryngologist Wilhelm Fliess, best-known for his association with Sigmund Freud; his older brother, (Wilhelm) Robert Fleiss, was a psychoanalyst and doctor and later emigrated to America. Konrad studied as a pupil under Erich Wolfsfeld at the Berlin Academy but, probably on account of racial persecution in Nazi Germany, fled to England in 1939 at the outbreak of the Second World War.
In England, unusually, he was apparently exempted from the internment of so-called 'enemy aliens' in June 1940 (although it is not known on what grounds) and served throughout the conflict in the Pioneer Corps, afterwards continuing his painting studies under Clifford Hall at the Regent Street Polytechnic in London between 1947 and 1949. Fliess focused on portraiture, landscape and still life, handled in a painterly manner, at times demonstrating the legacy of German Expressionism. In 1954 he held a solo exhibition at Derby Art Gallery, also exhibiting with the Royal Institute of Oil Painters, the Artists of Chelsea group (both in 1955) and the National Society (1956).
Charles W. Fliess died in England in 1956, at the age of 56. Three of his works were shown posthumously at the National Society exhibition at the Royal Institute galleries the same year, where his work was reviewed by the critic of the Jewish Chronicle, who noted his 'individual line' and that his 'small output showed a happy marriage of intellect and emotion'. Eight of his works were acquired posthumously by the Friends of the Art Museums of Israel and exhibited at Ben Uri Gallery in February 1958 prior to their despatch to the Bezalel Museum, Ein Harod Museum and Tel Aviv Museum in Israel. His work is also held in UK collections including Alfred East Art Gallery, the Ben Uri Collection, Dudley Museums Service, Leamington Spa Art Gallery and Wolverhampton Art Gallery.