The region was part of the medieval
State of the Teutonic Order. After population decline in the wake of wars in the 15th century and partition of the Teutonic state to Polish part, German peasants from neighboring
Farther Pomerania settled in the Schlochau region, which became German-speaking in majority. As the result of the
Partitions of Poland, the region became part of Prussia. The Schlochau district was created as a district within the
Marienwerder Region on 1 April 1818, as a result of administrative reforms in the
Kingdom of Prussia after the
Napoleonic Wars. The Marienwerder Region formed part of
West Prussia between 1815 and 1829 and again from 1878 to 1920, between the two periods the region, and thus Schlochau district, formed part of the
Province of Prussia. The district encompassed most of the rural environs around Schlochau, where the district president had his office. Following the dissolution of West Prussia after
World War I and the
Treaty of Versailles, the Schlochau district became part of
Schneidemühl Region in the newly established
Frontier strip of Posen-West Prussia province. The northeastern part of the district was transferred to the
Second Polish Republic. When Posen-West Prussia was dissolved on 1 October 1938, the Schlochau district was transferred to
Province of Pomerania and formed part of its new
Frontier strip of Posen-West Prussia region, which was actually the Schneidemühl Region enlarged by four previously Brandenburgian and Pomeranian districts and renamed as
Posen-West Prussia Region for reasons of tradition. On 1 January 1939, the district was renamed from Kreis Schlochau to Landkreis Schlochau, in the course of uniforming the administrative terminology in all the states of Germany. The Schlochau district was conquered by the
Soviet Red Army in 1945 during
World War II. It was subsequently dissolved after being placed under Polish administration according to the post-war
Potsdam Agreement. == Demographics ==