To this day, the disputes between historians on the subject of early onset of the building of metropolitan type in the Slupsk castle-town continue. Some of them consider that the castellany was found on the right side of the Slupia river (in the place of 19th century church of St. Otto), other by contrast locate it in the former Dominican friars cloister, so in the actual place of the castle. However, it is sure that the castle-town existed in 9th century and performed its duties until 14th century, when in 1265, on another bank of a river, a town on German law was established. About 1392, Wartislaw VII began the building of his own residence near the Fishermen Gate within the city walls.

Unfortunately, a spatial arrangement of this building is not known, but one can suppose that this was the dimerous building. About 1507, the prince Boguslaw X built the new residence for himself. This was his residence and since then it was called a castle. The building was arranged in a way that its south façade was situated at the line of the city walls, while from the direction of the town, high towers, which were later repeatedly rebuilt, were added to its shape. The ducal residence was raised on rectangle location 16,5 x 35 meters; it was also the cellar and two - storeyed building.

From the plan of that time town it can be assumed that the castle square together with the chapel and other outbuildings took the place of build-up area in the south town district and was separated with a wall. About 1580÷1587 the duke John Frederick gave the order to rebuild the castle by Italian architects and stone-cutters (employed at the building of the Renaissance castle in Stettin).

The castle building was increased with one storey. The interiors were allocated with vaultings and ceilings, in the tower stairs were put and parquet floors were marbleized. From east side of the tower little loggia was established. Smooth eastern and western walls of the castle were decorated with bay windows, however the south wall – with small out jets. The angles of the building were divided with decorative grooves. The whole was covered with the four-slope roof on which the roofing clay shingle was put and was brought from Slawno.

Internal walls of the castle were decorated with the cordovan, while its interiors were decorated with numerous works of art, brought later to Stettin, and then to Berlin in 1731. The castle was devastated in 1815÷1821, when it was exchanged by Prussian authorities on the warehouses of salt and cereal. In the beginning of 19th century the castle was given to many various adaptations. After the thunderbolt in 1815, the tower was partly decomposed, the fourth short storey was overbuilt. The big windows were bricked up and in their place numerous smaller windows were built. The rooms of the castle were completely transformed, walls and vaults were destroyed and the storey based on wooden pillars was created.

Shortly before the war, the theatrical props and decoration were stored in the castle rooms. During The Second World War the castle became almost completely damaged. After the war, the factory of ropes and nets in the castle was situated. In 1951 first maintenance works, protecting the castle before the complete ruin, were carried out. In the 1959-1965 the castle was rebuilt to the architectonically form, which it had in 16th century. Since 1965 The Museum of the Middle Pomerania in Slupsk is placed in the castle.