Background
Karl Grünberg was born on November 5, 1891.
Karl Grünberg was born on November 5, 1891.
He served as secretary of German Proletarian Writers’ Union.
In 1911, he joined Social Democratic Party of Germany. Then, in 1919 he moved to Independent Social Democratic Party of Germany. A year after (1920) he settled with communists by joining the Communist Party of Germany.