Berlin's history has left the city with an eclectic assortment of architecture. The city's appearance in the 21st century has been shaped by the key role the city played in Germany's 20th-century history. Each of the governments based in Berlin—the Kingdom of Prussia, the 1871 German Empire, the Weimar Republic, Nazi Germany, East Germany and the reunified Federal Republic of Germany—initiated ambitious construction programs, with each adding its distinct flavour to the city's architecture.