Until 1922 he was a paid functionary of the KPD in Württemberg. At the Fourth World Congress of Komintern he participated as a delegate. In 1923 he worked in the military wing of the KDP and was then M-Leader of the Wasserkante during Hamburg Uprising. In 1924 he attended the military school in Moscow; in the same year he became leader of the newly founded Roter Frontkämpferbund (RFB) and editor in chief of its newspaper, the "Rote Front". In 1927 he was dispatched to the 11th party congress of the KDP in Essen.