of Merit 3rd Class, and on 23 November 1914 was taken prisoner of war by the Russians during a "spirited" attack that he had ordered. As he wrote to fellow Social Democrat Karl Seitz, who sent him money through friends in Stockholm, he was able to work on a comprehensive theoretical treatise during his imprisonment in Siberia. He was also allowed to read Russian, English, and French newspapers due to his privileges as an officer, and he did not have to engage in physical labor. As a result of intervention by the SDAP, Bauer was able to return to Vienna as an exchange invalid in September 1917, less than two months before the outbreak of the October Revolution in Russia. In February 1918 he was appointed first lieutenant in the reserves and in March placed on leave from active military service in order to work on the . He was formally in army service until 31 October 1918. His contacts with Menshevik functionaries while a prisoner of war had made him a staunch supporter of the "Marxist center" that the Mensheviks represented. In Austria, however, his views placed him among the left (Marxist) wing of the SDAP. Rise to leadership in the SDAP The SDAP's left wing had gained in importance at the party congress in 1917 because the plight of the civilian population that was going hungry due to wartime food shortages. The assassination in the fall of 1916 of the unpopular imperial Minister President Karl von Stürgkh by Friedrich Adler, son of SDAP chairman Victor Adler, also spurred on the opponents of Burgfriedenspolitik, a political truce under which the parliamentary parties refrained from challenging the Empire's war policy. Following Stürgkh's assassination, the SDAP began increasingly to distance itself from the government's wartime course. The Russian October Revolution once again increased the importance of the left wing when it was assigned the task of preventing Austrian workers from moving over to the Bolsheviks. After Victor Adler's death on 11 November 1918, the 37-year-old Otto Bauer, seen as the young and dynamic leader of the SDAP's left wing, was brought into the party's leadership. As a counterweight, the leader of the SDAP's right wing, Karl Renner, was given the position of Chancellor on 30 October 1918 in the first government of the new state of German-Austria, which declared itself both a republic and part of the German Republic on 12