The Prussian land and building cadastre was introduced on May 21, 1861, under three laws that unified the tax system throughout the Prussian state. According to the regulations, the cadastre was to be based on measurements and calculations. Because broad field surveys were not taken into account, cadastral maps drawn up at that time were most often copies of already existing land maps. In the 1930s, the Prussian state reorganized its surveying services, aimed at introducing a uniform system of land classification in the entire German state, and consequently a single cadastral system. As a result, a unified state cadre - the Reichkataster – was to be formed throughout Germany. Unfortunately, the work did not produce the desired effect and the Reichkataster was introduced only in 1941. Further work on the national cadastre was interrupted by the Second World War. The State Archive in Olsztyn holds the cadastral documentation from the area of the former Olsztyn district, the part of the Królewiec district (primarily the area which after the Second World War was within the borders of the Polish state) and the remains of the cadastral office in Węgorzewo. The full documentation from the area of the Królewiec district is presented, consisting of cadastral office files and 9 cadastral offices in Bartoszyce, Braniewo, Gierdawy, Kętrzyn, Lidzbark Warmiński, Morąg, Pasłęk, Pruska Iława and Święta Siekierka. There are 11222 cadastral maps in the file. This documentation is an important part of the pre-war resource of Olsztyn.