He participated, as a delegate from Dortmund, in the "founding congress" of the Communist Party which took place over three days in Berlin, starting on 31 December 1918. In 1920 he became party chairman for the Essen district and took a paid secretarial position with the party. During the abortive (and brief) Ruhr uprising which broke out in March 1920 he took a leading role in the Ruhr Red Army.