and Stefan on 7 December 1926. In Saargemünd the family lived in a small apartment at Neunkircherstraße 19; due to their financial situation they had to give up their Berlin apartment at the end of February 1915. At the end of August, 1916, Döblin was awarded the Fontane Prize (including a monetary award of 600 Marks) for The Three Leaps of Wang Lun (Die drei Sprünge des Wang-lun). Following this recognition, Döblin set himself to work on his historical novel Wallenstein, set during the Thirty Years' War. Döblin had to interrupt work on the novel in March 1917 because he had caught typhus, but was able to use the university library at Heidelberg during his convalescence in April and May to continue researching the Thirty Years' War. Back in Saargemünd he came into conflict with his superiors due to the poor treatment of the patients; on 2 August 1917 he was transferred to Hagenau (Haguenau) in Alsace, where the library of nearby Strassbourg helped complete Wallenstein by the beginning of 1919. At the beginning of 1919, Döblin moved into his new apartment and medical practice at Frankfurter Allee 340 in Berlin. The immediate postwar period was a turbulent time for him—his financial situation was dire, and the death of his sister Meta on 12 March 1919 as the result of an injury sustained during skirmishes between the Spartacists and nationalist troops in Berlin showed how volatile the situation in Germany was in the aftermath of the November Revolution. The years during and immediately after the war also marked Döblin's growing politicization; although he never joined a party he identified with the political left. During this time Döblin wrote a number of satirical and polemical political essays under the pseudonym "Linke Poot," a dialectical variation of "Linke Pfote" (Left Paw), eleven of which were published in 1921 in a volume called Der deutsche Maskenball (The German Masked Ball). In February 1921, he met the 21-year-old photographer Charlotte ("Yolla") Niclas; the close romantic relationship between the two was to last many years, despite their age difference. The same year, following a family vacation to the Baltic coast, he began preparatory work on his science fiction novel Berge Meere und Giganten (Mountains Seas and Giants), which would be published in 1924. In 1920 Döblin joined the Association of German Writers (Schutzverband Deutscher Schriftsteller), and in 1924 he became its president. In November 1921