Marchlewszczyzna was the Polish National District (Мархлевский польский национальный район) in Ukraine created as an experiment and as part of the Soviet Korenizatsia campaign on 21 July 1925 in Zhytomyr Okruha on resolution of Little Presidium of the All-Ukrainian Central Executive Committee. Its capital the town of Dovbysh, later in 1926, was renamed as Marchlewsk. The district was one of 32 other national districts that were created in the Ukrainian SSR during that period (1924-1939). Creation of the district was based on standards adopted by the 4th session of the All-Ukrainian Central Executive Committee (15-19 February 1925) and recommendations of Central Commission in affairs of National Minorities at that executive committee. It was created to implement an idea in creation of Polish national districts on territories of Ukrainian and Belarusian SSRs.