Brandenburg is one of the sixteen federal-states of Germany. The capital is Potsdam.It lies in the east of the country and is one of the federal states that was re-created in 1990 upon the reunification of the former West Germany and East Germany. Brandenburg surrounds but does not include the national capital and city-state Berlin. Originating in the medieval Northern March, the Margraviate of Brandenburg grew to become the core of the Kingdom of Prussia, which would later become the Free State of Prussia. The eastern third of historic Brandenburg (Ostbrandenburg/Neumark) was ceded to Poland in 1945.