Bertolt Brecht, born in 1898 in Augsburg, begins working on The Downfall of the Egoist Johann Fatzer in Berlin at the end of 1926. Although the material he collects under this title over the following years spans many hundreds of pages and he works intensively on it in several phases, Fatzer is never completed. During these years, Brecht operates on two fronts: on one hand, he studies the theories of political economy with great interest and attempts in several efforts to create stage-worthy texts from them. On the other hand, he collaborates with Kurt Weill in 1927 to write his opera Rise and Fall of the City of Mahagonny, shortly thereafter creating his most successful play, The Threepenny Opera. The Fatzer material contains many leitmotifs and frequently reused ideas from Brecht, including his famous Keuner figure, which he develops in this context.