 In 1815 it was annexed by Prussia again, first it became part of the Grand Duchy of Posen, but in 1817 was incorporated into the province of West Prussia.Following the Treaty of Versailles, Chełmno Land was returned to Poland in January 1920, after the Poles regained independence in 1918.In the interwar period it formed the southern part of the Pomeranian Voivodeship with the capital in Toruń.