 In 1454, King Casimir IV Jagiellon reincorporated the Chełmno Land to the Kingdom of Poland upon the request of the Prussian Confederation, however, Łasin itself was captured by Poles in 1461 during the subsequent Thirteen Years' War.After the war, in 1466, the Teutonic Knights renounced claims to the town, and recognized it as part of Poland.Administratively it was located in the Chełmno Voivodeship in the province of Royal Prussia in the Greater Poland Province of the Polish Crown.