Peter Ulrich Weiss (8 November 1916 – 10 May 1982) was a German writer, painter, and artist of adopted Swedish nationality. He is particularly known for his plays Marat/Sade and The Investigation and his novel The Aesthetics of Resistance. Weiss was born in Nowawes (now part of Potsdam-Babelsberg), Brandenburg, to a Hungarian Jewish father and Christian mother. At age three he moved with his family to Bremen, and then during his adolescence to Berlin where Weiss began training for a career as a visual artist. In 1934 he emigrated with his family to Chislehurst, near London, England, where he studied photography at the Polytechnic School of Photography, and then in 1937-1938 attended the Prague Art Academy. After the German occupation of the Sudetenland in 1938, his family moved to Sweden, and Weiss himself removed to Switzerland. In 1939 he again emigrated to Stockholm, Sweden, where he lived for the rest of his life. He became a Swedish citizen in 1946. Weiss was married three times: to the painter Helga Henschen, 1943; to Carlota Dethorey, 1949; and to the hereditary baroness Gunilla Palmstierna, 1964.