Lower house of the German bicameral legislature. It represents the nation as a whole and is elected by universal suffrage under a system of mixed direct and proportional representation. Members serve four-year terms. The Bundestag in turn elects the chancellor. The term was formerly used to refer to the federal Diet of the German Confederation (1815-66), known as the Reichstag under the Weimar Republic (1919-34). Its building burned down in 1933 (see Reichstag fire), and its members were not allowed to meet again for the duration of the Nazi regime (1933-45). The Reichstag was reconstituted as the Bundestag in the governmental reorganization of 1949. Its membership was again reorganized after German unification in 1990