At the end of the 20th century and the beginning of the 21st century, renovation works were conducted on the complex of the market square development traditionally called the Old Town Hall (Stary Ratusz) in Olsztyn. The work on the south wing of the complex included removal of plaster. The gothic face of the walls emerged from beneath the plaster. The discovery of medieval construction was unexpected. The tradition of historians of Olsztyn was dominated by the opinion that the Olsztyn town hall building was burned down in 1621.
The authors of the article, at that time acting as conservation supervisors over the works, inspired by the discovered artefact, initiated architectural research. The work included examination of documents, iconography, and verification of formulated conclusions on the existing structure. As a result of these tasks, it was determined that the remaining structure, despite several reconstructions, may have originated from the second half of the fourteenth century.
During the research activities, it was determined that the gothic face of the building was covered in circa 1770. In this period the western gable of the building collapsed and renovation works related to its reconstruction were initiated. The new wall was erected on the new foundation. These works took place during the first partition of Poland. Warmia, including Olsztyn, was taken over by the Prussian administration. It is possible that the intent to hide decorations foreign to the “Teutonic spirit” in ox spine, was the reason for the decision ordering to plaster the structure. From this time, the documents mention that there is no gothic town hall in Olsztyn. This state lasted for over two hundred years, until the time when the medieval construction was uncovered from beneath the layers of plaster.
During the research works it was discovered that the remaining building originally served as a trading house. Similar, usually two storey trading houses, known as smatruzy, constituted market square development of medieval cities in Silies and other western cities. Very often, in the later period the floor of many such trading houses was adopted for a council room, as in the building in Olsztyn.
During the adaptation of the first floor the eastern gable of the building was reconstructed into the council chambers. After this reconstruction it obtained the decoration in ox spines.
Currently, after conservation works, the magnificent medieval building fills the Olsztyn market square, next to the cathedral, and together with the Cathedral, the city gate and the chapter house, supplements the urban program of the medieval city within the limits of the protective wall relics.