 The city was liberated by the Red Army on 27 July 1944 and on 20 September 1944 transferred to Poland . After the war , the city became capital of the initial Białystok Voivodeship ( 1945 – 1975 ) of the People 's Republic of Poland . After the 1975 administrative reorganization , the city was the capital of the smaller Białystok Voivodeship ( 1975 – 1998 ) . Since 1999 it has been the capital of the Podlaskie Voivodeship , Republic of Poland . 
