before the 18th century bigger half of the oblast belonged to the kiev (kijow) voivodeship, while smaller western half around the city of zviahel (novohrad-volynskyi) belonged to the volhynian (wolyn) voivodeship. following the treaty of andrusovo, the city of zhytomyr (zytomierz) continued to act as an administrative center of the kiev voivodeship.