(real name, Efroim Truskier; party pseudonyms, Berent, Dżek, and Keller). Born Sept. 12, 1880, in Warsaw; died there Nov. 27, 1956. Figure in the Polish working-class movement. Historian, economist, and publicist.
Fiedler studied at the Universities of Berlin and Zürich. In 1905 he became a member of the Social Democracy of the Kingdom of Poland and Lithuania (SDKPL), and from 1916 to 1918 he was a member of its Central Board. He took part in the Revolution of 1905–07 in the Kingdom of Poland and organized revolutionary trade unions in 1906. From 1908 to 1918 he edited a number of publications of the SDKPL.
In 1918, Fiedler joined the Communist Party of Poland (CPP). From 1918 to 1930 he served as a member of the Central Committee of the CPP and supervised the party’s publishing activities. He spent 1938 to 1945 in France, where in 1944 and 1945 he took part in the work of leftist Polish organizations in Paris. In 1945 he became a member of the Polish Workers’ Party (PWP) and of the party’s Central Committee. In 1948 he joined the Polish United Workers’ Party (PUWP) and became a member of the Central Committee. From 1947 to 1952, Fiedler was editor in chief of Nowe Drogi, the organ of the Central Committee of the PUWP, and from 1949 to 1953 he served as chairman of the Central Committee’s Commission on Science. In 1952 he became a member of the Presidium of the Polish Academy of Sciences.
WORKSW sprawie chlopskiej. [Warsaw] 1932.
Luksemburgizm a kwestia chlopska. [Warsaw] 1932.
Historyczne znaczenie konstytucji 3 Maja, 2nd ed. [Lódź] 1946.