one of the two legislative chambers of the Federal Republic of Germany. The Bundestag is the Lower House, representing the nation as a whole and 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 (prime minister), who is the head of government. It meets in the Reichstag building in Berlin. The term Bundestag also was applied to the federal Diet of the German Confederation (1815–66).