Berlin is a place.
Berlin ( [ bəɹˈlɪn ] , [ bɛɐ̯ˈliːn ] ) is the capital and the largest city of Germany as well as one of its 16 constituent states . First documented in the 13th century and situated at the crossing of two important historic trade routes , Berlin became the capital of the Margraviate of Brandenburg ( 14171701 ) , the Kingdom of Prussia ( 1701 -- 1918 ) , the German Empire ( 1871 -- 1918 ) , the Weimar Republic ( 1919 -- 1933 ) and the Third Reich ( 1933 -- 1945 ) . Berlin in the 1920s was the third largest municipality in the world . Following German reunification in 1990 , Berlin once again became the capital of all-Germany .