During the November revolution he was active in the soldiers´ councils, working closely together with anarchist writer and activist Erich Mühsam. Levien became chairman of the Munich Soldiers´ Council and the Munich Spartacus group. He participated as a delegate for Munich in the founding convention of the Communist Party of Germany (KPD) over the New Year 1918-19, and became party chairman for KPD in Bavaria. Levien was together with Eugen Leviné one of the leaders of the second phase of the Soviet Republic after the suppression of the right-wing counter-coup on Palm Sunday 13 April 1919. Unlike Leviné, Levien was not of Jewish descent, but was nevertheless defamed as Jewish by political opponents. Levien was arrested after the suppression of the Soviet Republic, but managed to flee to Vienna in May 1919. There he was arrested again.