Karl Mannheim (March 27, 1893, Budapest - January 9, 1947, London) was a German-born sociologist, influential in the first half of the 20th century. 1914 he heard in Berlin Georg Simmel and worked from 1922 - 1925 in Heidelberg under the german sociologist Alfred Weber, brother of the very well known german sociologist Max Weber. One of his assistants was Norbert Elias (from spring 1930 until spring 1933).
Important work: Ideology and Utopia. Mannheim is seen as a founder for the sociology of knowledge.