Treaty of Warsaw
In 1701, Lauenburg/Lębork became a Prussian-administered territory under the sovereignty of the Polish Crown. The 1773 Treaty of Warsaw granted full sovereignty over the territory to Prussia after the First Partition of Poland. The Lauenburg and Bütow Land, transformed into a district ("Lauenburg-Bütowscher Kreis"), was first included in the newly established province of West Prussia, but was transferred to the province of Pomerania in 1777.